Mayor Jason Perry has called on the Government to seize a major national growth opportunity by commissioning a fresh assessment of rail capacity around East Croydon and Windmill Bridge Junction.
Previous modelling suggested that resolving this critical bottleneck could unlock around £5.1 billion in economic value over 20 years. The Mayor wants the Government to update that evidence and identify the most affordable and deliverable way to secure the benefits.
He has written to the Secretary of State for Transport calling for a renewed assessment of the Croydon Area Remodelling Scheme and other options for increasing capacity across the Thameslink Growth Corridor.
The junctions around East Croydon connect Brighton and Gatwick with central London, Luton, Bedford, Peterborough and Cambridge. Investment at this strategic pinch point could support new homes, jobs, airport expansion and private investment across a significant part of the UK economy.
Around 18% of national passenger journeys already take place on the Govia Thameslink Railway network. East Croydon handles more trains each day than all the intercity operators serving Euston, St Pancras and King’s Cross combined.
Demand is expected to grow considerably. The Brighton Main Line is forecast to reach full capacity by 2030, whilst passenger numbers could increase by 50% by 2045.
A Westminster Hall debate in March heard that addressing the Croydon bottleneck could unlock approximately £5.1 billion in economic value over the following two decades.
Major investments are already planned along the corridor. Gatwick Airport’s £2.2 billion Northern Runway project is expected to support around 14,000 jobs and generate an additional £1 billion a year for the economy. Every rail service between London and Gatwick passes through East Croydon.
Further north, Luton Airport is preparing for passenger numbers to reach 32 million a year, whilst the new Universal resort in Bedfordshire is expected to attract 8.5 million visitors in its first year and support around 28,000 jobs. Local authorities along the corridor are also expected to deliver approximately 34,000 homes each year.
Mayor Perry argues that these investments provide a compelling reason to address the infrastructure constraints that could otherwise hold back their full economic potential.
The previous Croydon Area Remodelling Scheme would have expanded East Croydon station from six to eight platforms, remodelled the surrounding tracks and junctions, removed conflicting train movements and supported improvements at Norwood Junction.
It was expected to provide capacity for between four and six additional trains an hour, increasing peak capacity by around 15%.
The original scheme was estimated to cost approximately £2.9 billion, take more than ten years to complete and cause substantial disruption during construction. These figures now need updating, but the potential economic return is too significant to leave unexamined.
The Government does not need to decide immediately whether to fund the previous scheme in full. Mayor Perry is asking it to invest in the development work needed to refresh the evidence, examine phased and alternative interventions and identify the best-value route to unlocking the corridor’s growth potential.
Mayor Jason Perry said:
“Growth does not happen through announcements alone. It depends on infrastructure that connects people to jobs, businesses to markets and investment to opportunity.
“Previous modelling suggested that resolving the Croydon bottleneck could unlock £5.1 billion in economic value. We are not asking ministers to approve the old scheme unchanged, but to update the evidence and identify the most affordable and deliverable way forward.
“This is far bigger than a Croydon transport project. Removing this strategic constraint could unlock jobs, homes and private investment across the corridor, from the south coast through London and on to Bedford, Peterborough and Cambridge. It is exactly the kind of long-term infrastructure decision a government serious about growth should be prepared to make.”
In his letter, the Mayor has asked the Government to:
- commission Network Rail to update its passenger-demand modelling, economic assessment and options for resolving the Croydon bottleneck;
- assess the full Croydon Area Remodelling Scheme alongside phased interventions capable of delivering earlier improvements;
- protect land already acquired or identified for the scheme;
- establish a joint working group involving the Department for Transport, Network Rail, Croydon Council, other corridor authorities, GTR, Gatwick Airport and business representatives; and
- develop a robust investment proposition for consideration at the 2027 Spending Review.
Mayor Perry previously brought together local authorities between Brighton and Croydon, with council leaders from different political parties agreeing on the need for government investment.
Following the recent local elections, he has asked authorities across the full corridor, from Brighton through Croydon to Bedford and Peterborough, to join a renewed cross-party campaign for investment.
The Mayor has also requested a meeting with the Secretary of State and Rail Minister to discuss how the work can be taken forward.
His full letter to the Secretary of State for Transport can be read here:
The Rt Hon Heidi Alexander MP
Secretary of State for Transport
Department for Transport
Great Minster House
33 Horseferry Road
London
SW1P 4DRDear Secretary of State,
Thameslink Growth Corridor, Brighton Main Line and Croydon Area Remodelling Scheme and the Windmill Bridge Junction bottleneck
I am writing to ask the Government to reopen the detailed examination of the Thameslink Growth Corridor, Brighton Main Line and Croydon Area Remodelling Scheme and commission a refreshed assessment of the investment needed to address the Windmill Bridge Junction (Croydon) bottleneck.
This is a nationally significant constraint on economic growth, rather than a narrowly local transport scheme. The Croydon bottleneck sits within the most congested part of the national rail network. It affects the Brighton Main Line, the wider Thameslink corridor and services linking London with Gatwick and Luton airports, as well as communities stretching from the south coast to Peterborough and Cambridge.
Around 18% of all national passenger journeys take place on the Govia Thameslink Railway network. East Croydon already handles more trains each day than all the intercity operators serving Euston, St Pancras and King’s Cross combined. The Brighton Main Line represents only 5% of Network Rail’s Southern region, but generates around 25% of its revenue.
The economic significance of this corridor will grow considerably over the coming years. Gatwick Airport’s £2.2 billion northern runway expansion is expected to support approximately 14,000 jobs and contribute an additional £1 billion a year to the economy. Every rail service between London and Gatwick passes through East Croydon, whilst Gatwick intends 54% of airport journeys to be made by public transport.
Further north, Luton Airport expects passenger numbers to reach 32 million by 2043 and Universal Studios’ proposed Bedfordshire resort is forecast to attract 8.5 million visitors annually and support 28,000 jobs. Local authorities along the Brighton Main Line are also expected to deliver approximately 34,000 homes every year.
The corridor is also expected to accommodate substantial housing growth over the coming decades. Without corresponding investment in transport capacity, the Government risks creating a mismatch between planned housing delivery and the infrastructure required to support sustainable communities.
The case for investment aligns directly with the new Government’s mission to deliver sustainable economic growth. The Thameslink-Gatwick-Cambridge corridor connects internationally significant economic assets including two major airports, London’s central employment market, the Cambridge Innovation Cluster and other emerging growth locations across the South East. The performance of this corridor has implications well beyond the communities it directly serves.
All this additional economic activity and passenger demand will have to pass through infrastructure which is already operating close to its limits. The Brighton Main Line is expected to reach full capacity by 2030, whilst passenger volumes are projected to increase by 50% by 2045.
Unless the Croydon bottleneck is addressed, there is a real danger that nationally important private investment will be constrained by inadequate public infrastructure. Poor reliability also damages the United Kingdom’s attractiveness to international investors, particularly when their first experience of the country is a disrupted journey between Gatwick and London.
The constraint at Windmill Bridge Junction is also a resilience issue. Disruption at Croydon can have cascading effects across the national rail network, affecting passengers and businesses for beyond South London. Addressing this long-recognised vulnerability would improve operational resilience on one of the country’s most strategically important transport corridors.
The previous Croydon Area Remodelling Scheme would have expanded East Croydon from six to eight platforms, remodelled the surrounding tracks and junctions, removed conflicting train movements and supported improvements at Norwood Junction. It was expected to provide capacity for four to six additional trains an hour and approximately 15% more peak capacity.
Previous modelling suggested that addressing the bottleneck could unlock around £5.1 billion in economic value over 20 years. The Brighton Main Line’s passenger volumes and revenues mean that investment in the Thameslink Growth Corridor also has the potential to generate significant farebox and Treasury returns, helping to support the wider national rail network.
I recognise that the original scheme was estimated to cost approximately £2.9 billion, take more than ten years to deliver and involve substantial disruption. I am not asking the Government simply to adopt a pre-pandemic design without further scrutiny. I am asking that the problem, the evidence and the available solutions are properly re-examined.
A refreshed programme of work should consider current and projected passenger demand, the cumulative impact of Gatwick and Luton expansion, Universal Studios, housing growth long the whole Thameslink Growth Corridor and major regeneration in Croydon. It should examine the full CARS proposal alongside any phased or alternative options capable of delivering earlier capacity, reliability and accessibility benefits as outlined recently in Network Rail’s Brighton Main Line: Strategic position and evidence base summary document (April 2026).
During the Westminster Hall debate in March, the Minister confirmed that the 2027 Spending Review would be an important opportunity to make the case for future investment and said that the Government looked forward to working with Brighton Main Line stakeholders. Croydon Council is ready to respond positively to that invitation.
I, therefore, ask the Government to:
commission Network Rail to refresh the demand modelling, economic assessment and options for resolving the Croydon bottleneck;
assess the full scheme alongside phased interventions and opportunities for earlier delivery;
ensure that land already acquired or identified for the scheme remains protected;
establish a joint working group involving the Department for Transport, Network Rail, Croydon Council, other corridor authorities, GTR, Gatwick Airport and business representatives; and
develop a robust submission for consideration at the 2027 Spending Review.
Investment in the South East should not be seen as competing with the Government’s ambitions for growth elsewhere. London and the South East together generate around a third of the country’s economic activity. Maintaining the infrastructure that supports that productivity helps generate the revenues needed to invest across the United Kingdom.
Regional growth depends on national infrastructure keeping pace. The economic opportunities along the Thameslink and Brighton Main Line corridor are substantial, but they cannot be fully realised whilst one of the most important parts of the railway remains constrained by a bottleneck that has been understood for many years.
Croydon is keen to work constructively with the Government, Network Rail and partners across the corridor to build the evidence, develop an affordable and deliverable solution, and demonstrate the significant economic and fiscal return this investment could provide. However, continued deferral of decisions risks allowing infrastructure constraints to become a brake on housing delivery, private investment, airport growth, and national performance.
I would welcome the opportunity to meet you and the Rail Minister to discuss how we can take this work forward.
Yours sincerely,
Mayor Jason Perry
Executive Mayor of Croydon
