Across the United Kingdom, mayors are increasingly turning to public-private partnerships (PPPs) as a strategic mechanism to finance and deliver major urban development projects. With central government budgets under persistent pressure and cities competing for investment, these collaborations offer a pragmatic route to build housing, upgrade transport networks, and regenerate public spaces. By combining public-sector oversight with private-sector capital and expertise, mayors are seeking to accelerate progress on some of the most pressing challenges facing Britain’s cities, from the housing crisis to net-zero infrastructure.

This approach is not new – the UK has used private finance for public projects since the Private Finance Initiative (PFI) of the 1990s – but the role of directly elected mayors, particularly those with combined authority powers, has given PPPs a fresh impetus. Mayors in areas such as Greater Manchester, the West Midlands, and London now hold significant influence over transport, housing, and economic development, making them key players in structuring and promoting partnership-based schemes.

What Are Public-Private Partnerships?

Public-private partnerships are contractual arrangements in which a private entity takes on the design, construction, financing, and operation of a public project – often over a 25- to 30-year period. In return, the private partner receives revenue streams, typically from the public sector in the form of unitary charges, or from user fees such as tolls or ticket sales. The core idea is to share risks and rewards: the public sector gains access to upfront capital and private-sector innovation, while the private partner gets a predictable, long-term return on its investment.

The UK has applied PPPs across diverse sectors – from schools and hospitals to roads and rail. Modern PPP models have evolved to include lighter-touch variants such as design-build-finance-maintain (DBFM) contracts, as well as more flexible revenue-sharing agreements. For mayors, the appeal is clear: PPPs can deliver infrastructure years sooner than traditional procurement, and can often bring in cutting-edge technology and operational efficiency that public bodies may lack internally.

For a deeper overview of PPP structures, the Institute for Government provides a useful explainer on the history and models of private finance in public projects.

How Mayors Are Using PPPs in Urban Development

Mayors across the UK are deploying PPPs to address specific urban challenges. While each city’s priorities differ, three areas have emerged as the most common focus: housing, transport, and public spaces.

Housing Developments

The UK faces a chronic shortage of affordable housing, and mayors are using PPPs to unlock stalled sites and accelerate delivery. In Greater Manchester, Mayor Andy Burnham’s Housing Strategy has relied on joint ventures with private developers to deliver thousands of mixed-tenure homes, including a significant proportion of affordable units. By contributing land from public ownership and streamlining planning approvals, the combined authority lowers the risk for private partners, making schemes financially viable that would otherwise not proceed.

Similarly, in the West Midlands, Mayor Richard Parker has championed partnership models that tie housing delivery to infrastructure improvements. A PPP framework ensures that new housing developments are accompanied by necessary roads, schools, and green spaces, funded partly through developer contributions and partly through public grants. This integrated approach avoids the piecemeal development that has often blighted urban fringes.

Birmingham’s Perry Barr regeneration, linked to the 2022 Commonwealth Games, offers a prominent example. The council partnered with a private consortium to redevelop a large area into a new residential and commercial district, delivering over 1,000 homes alongside new transport links and a public realm. The PPP structure enabled rapid procurement and construction, meeting the Games deadline while creating a long-term asset for the city.

Transport Infrastructure

Transport is a classic PPP domain, and UK mayors are increasingly using these partnerships to extend and upgrade their networks. London’s Crossrail (now the Elizabeth line) was delivered partly through a PPP model – though its structure was unusually complex. More recently, mayors have focused on smaller-scale but critical projects such as bus rapid transit systems, cycle networks, and suburban rail improvements.

In the West of England, Metro Mayor Dan Norris secured a PPP for the Ashton Gate to Temple Meads mass transit scheme, combining public funding with private investment in rolling stock and systems. The partnership framework allowed the project to move forward two years earlier than traditional funding cycles would have permitted.

Manchester’s tram network expansion also relies on PPPs. The Transport for Greater Manchester authority has used design-build-finance-maintain contracts for several Metrolink extensions, transferring construction risk to private consortia while retaining long-term control over fares and service quality. This model has proven cost-effective: the Oldham and Rochdale line extension was delivered 15% under budget compared to conventional procurement benchmarks.

Public Spaces and Cultural Venues

Revitalising parks, squares, and cultural venues is another area where mayors are leveraging private investment. Bristol’s redevelopment of the Harbourside, for example, involved a PPP between the city council and a developer to transform derelict docks into a mixed-use waterfront with public promenades, restaurants, and apartments. The private partner funded the bulk of construction, while the council provided planning certainty and ongoing maintenance of the public realm.

In Liverpool, Mayor Steve Rotheram has overseen the renewal of the city’s historic waterfront through a partnership with the Liverpool City Region Combined Authority and private investors. The creation of the Exhibition Centre Liverpool and the expansion of the Titanic Hotel were enabled by a PPP that shared revenue from event hosting. These projects have boosted tourism and created hundreds of jobs, demonstrating that PPPs can support both economic growth and public enjoyment of urban space.

Birmingham’s redevelopment of The Square – a central public plaza – involved a local business improvement district (BID) partnering with the city council to fund improved lighting, seating, and events programming. While not a large-scale infrastructure PPP, this smaller model shows how private businesses can contribute directly to placemaking.

Benefits of PPPs for Urban Growth

The advantages of PPPs for city development are well documented, but they need to be evaluated critically. Here are the principal benefits that mayors typically cite.

Accelerated Project Delivery

Traditional public procurement can be slow – months or years pass between project conception and ground-breaking. PPPs compress this timeline because the private partner has strong incentives to complete quickly and start generating returns. In Manchester’s MediaCityUK development, the PPP framework allowed the first phase to open within four years, compared to an estimated seven years under a purely public approach. This speed is especially valuable for mayors who face short electoral cycles and need to demonstrate tangible results.

Cost Efficiency and Risk Transfer

PPPs shift many risks – construction delays, cost overruns, operational performance – from the public sector to the private partner. Because private firms are better equipped to manage these risks and can achieve economies of scale, projects are often delivered more cost-effectively. A study by the National Audit Office found that properly structured PFI and PPP projects in the UK were 60-70% more likely to be delivered on time and on budget compared to traditional contracts. However, critics note that the long-term debt servicing can offset these gains; careful structuring is essential.

For mayors, the ability to attract private capital also reduces the immediate strain on council budgets. Since the UK government sets limits on local authority borrowing, PPPs allow cities to proceed with major projects without exceeding fiscal constraints. This is particularly valuable for mayors of regionally important cities that lack the central funding of London.

Access to Innovation and Expertise

Private partners often bring specialist knowledge that local government cannot maintain in-house. In smart city projects – such as Bristol’s deployment of IoT sensors for air quality monitoring – a PPP with a technology firm provided cutting-edge equipment and data analytics that the city could not have developed alone. Mayors are increasingly using these partnerships to pilot new approaches to energy efficiency, digital connectivity, and green infrastructure.

For example, the Greater London Authority’s partnership with Microsoft to create a "digital twin" of the city for planning simulations combines public objectives with private technological capability. The resulting tool helps decision-makers visualise the impact of new developments on transport, air quality, and energy use – an innovation that would have been prohibitively expensive for the public sector to develop independently.

Challenges and Considerations

Despite these benefits, PPPs are not a panacea. Mayors must navigate significant challenges, and poorly structured partnerships can entrench long-term liabilities for taxpayers.

Complex Negotiations

Drafting a PPP contract that balances risk and reward for both parties is notoriously difficult. The legal and financial complexity often requires costly advisors, and negotiations can stretch on for years. The UK’s early PFI hospitals were criticised for locking the NHS into inflexible contracts that made it hard to adapt services. Mayors must therefore invest in robust in-house capability to negotiate on equal terms with private consortia, which often have deep legal and financial resources.

In many combined authorities, this expertise is still being built. The West Midlands Combined Authority established a dedicated PPP unit in 2022, but smaller city regions may lack the bandwidth to manage the process effectively. Transparency around contract terms is equally critical; the public must be able to scrutinise the value for money and long-term costs of any partnership.

Long-Term Commitments and Flexibility

PPPs typically run for 25 to 30 years or more. During that period, political priorities can shift, economic conditions can change, and technology can evolve. A tram PPP agreed in 2010 may look very different in the context of 2030s electric autonomous vehicles. Mayors need to build flexibility into contracts – through break clauses, renegotiation triggers, or technology refresh mechanisms – to avoid being locked into outdated solutions.

The collapse of Carillion in 2018 demonstrated the risks of over-reliance on a single private partner. Several hospital and road PPPs had to be rescued by the public sector, exposing taxpayers to cost overruns. Mayors must ensure they have contingency plans and financial reserves to handle such scenarios, and should avoid putting all their development eggs in one private basket.

Public Accountability and Value for Money

Because PPPs involve long-term public payments to private companies, they can be seen as a form of off-balance-sheet borrowing. The National Audit Office has repeatedly flagged that PPPs are often more expensive than direct public borrowing in the long run, due to higher private finance costs. Mayors must therefore ensure that any PPP offers demonstrable value for money – not just through budget cost avoidance today, but through genuine risk transfer and operational benefits that justify the higher financing cost.

Public transparency is equally important. The UK’s Freedom of Information Act can apply to some PPP contracts, but many contain confidentiality clauses that limit scrutiny. Elected mayors have a particular responsibility to be open with constituents about the terms, costs, and performance targets of any partnership. Engaging citizens in the planning phase – through digital platforms or public meetings – can build trust and help identify potential pitfalls early.

For guidance on governance best practices, the Institution of Civil Engineers offers resources on maintaining accountability in PPPs.

Case Studies in UK Cities

Several UK city regions provide instructive examples of PPPs in action. These illustrate both the potential and the practical realities of partnership-based development.

London: Crossrail and the Elizabeth Line

London’s Crossrail project – the largest infrastructure project in Europe – was partly financed through a PPP between Transport for London (TfL) and a private consortium responsible for delivering the core tunnels and stations. The project faced significant delays and cost overruns, partly due to the complexity of integrating multiple private contracts. However, once operational, the Elizabeth line has transformed travel across the capital, boosting capacity by 10% and generating billions in economic benefits. The lessons from Crossrail have influenced how other mayors approach large PPPs, particularly around risk allocation and oversight.

Manchester: MediaCityUK

MediaCityUK in Salford Quays is a flagship example of urban regeneration through a PPP. The project was delivered by a joint venture between Peel Holdings (private) and the BBC (public), with support from Salford City Council and the Northwest Development Agency. It transformed a former docklands into a thriving media and technology cluster, home to the BBC, ITV, and hundreds of creative businesses. The key success factor was a flexible partnership structure that allowed the public sector to provide land and infrastructure while the private partner managed construction and commercial development. The result is a world-class digital hub that contributed over £1 billion to the regional economy within its first decade.

Bristol: Arena and Baltic Wharf

Bristol’s effort to build an arena – later renamed the Bristol Beacon for the renovated music venue – initially used a PPP model. The city council partnered with a private developer to construct a large entertainment venue on Baltic Wharf, but the project was eventually cancelled after protracted negotiations over risk-sharing. The failure underscores how difficult it is to align interests in large-scale arenas, where revenue projections are inherently uncertain. However, the city later successfully secured a PPP to renovate the existing Colston Hall (now Bristol Beacon) using a simpler funding model, demonstrating that flexibility in partnership structure is key.

More broadly, Bristol has pioneered using PPPs for smaller urban interventions. The Bristol City Council parks PPP for Castle Park involved a private company managing maintenance and events in exchange for a share of catering and hire income. This model has freed up public funds for other priorities while keeping the park well-maintained.

Birmingham: Commonwealth Games Legacy

Birmingham used PPPs to deliver much of the infrastructure for the 2022 Commonwealth Games, including the refurbished Alexander Stadium and the Athletes’ Village in Perry Barr. The village was built by a private developer under a agreement that guaranteed the developer a long-term revenue stream from renting the units as student accommodation post-Games. This innovative structure allowed Birmingham to avoid upfront capital costs while still delivering high-quality housing that will serve the city for decades. However, post-Games occupancy has been lower than expected, demonstrating the risk that demand forecasts may not materialise – a risk shared by both partners.

Future Outlook

As the UK’s mayoral powers continue to expand through devolution deals, the use of PPPs in urban development is likely to increase. Several trends will shape this evolution.

First, the climate emergency is driving demand for green infrastructure – from district heating networks to electric vehicle charging points – that often requires significant upfront investment. PPPs can unlock private capital for these projects, especially where revenue can be generated through user charges or energy savings. The Greater Manchester Combined Authority’s pioneering approach to retrofitting public buildings using a PPP for energy efficiency is likely to be replicated in other city regions.

Second, the government’s Levelling Up agenda is channelling funding through mayoral combined authorities, many of which will need to complement grants with private investment to achieve their ambitions. The £4.8 billion Levelling Up Fund encourages local areas to submit bids that leverage private co-investment, effectively incentivising PPP formation.

Third, mayors are exploring more flexible partnership models, such as social impact bonds and municipal bonds co-issued with private partners, to reduce reliance on traditional PFI-style structures. The Liverpool City Region’s recently established Urban Innovation Fund uses a blended finance model, mixing public grants, private equity, and impact investment to support small-scale urban projects.

However, the success of future PPPs will depend on three factors: robust governance frameworks, genuine community engagement, and a willingness to learn from past mistakes – both domestic and international. For a comparative perspective, the OECD’s PPP knowledge hub provides case studies and guidance that UK mayors can draw on.

In conclusion, public-private partnerships offer mayors a powerful but imperfect tool for driving urban development. When used strategically – with clear objectives, balanced risk allocation, and transparency – they can deliver transformative projects that neither the public nor the private sector could achieve alone. As UK cities navigate the intersecting challenges of housing shortages, ageing infrastructure, and climate resilience, the mayoral-led PPP model will remain a central feature of the urban development landscape.