Every fast train between the Gatwick Diamond region and London squeezes through a tangle of junctions at Croydon. Fixing them is one of the single steps we can take for jobs, homes and growth across our region. Here is how Parliament is pushing for it, and how your business can help.
By Geri Silverstone, Secretariat to the APPG for the Southeast and Gatwick Diamond Growth Gateway
One pinch point, holding a whole region back
If you run a business within the Gatwick Diamond region you will already know that the Brighton Main Line matters. It carries more than 300,000 passengers every weekday. It makes up just 5% of the Southern Region network but brings in around a quarter of its revenue.
What fewer people know is where the line is held back. At East Croydon, Selhurst and Norwood Junction, Southern, Thameslink and Gatwick Express trains all have to cross each other’s paths on flat junctions, with too few platforms and too little track. It is one of the most congested points on Britain’s railway.
When something goes wrong at Croydon, it does not stay there. Because Thameslink runs right through London, one late train can delay services from the Sussex coast to Bedford, Peterborough and Cambridge. For our staff and customers, that means missed meetings, late shifts and crowded carriages.
The cost to our economy and to jobs
Rail reliability decides how far people will travel for work, how easily firms recruit, and whether investors choose our region. Peak demand for fast trains into London is forecast to grow by between 19% and 49% by 2045. Some peak passengers already stand for more than 20 minutes. Without new capacity, the share of commuters standing that long is expected to double, and could triple.
When the railway fails, people turn to already congested roads, and the region’s growth suffers. Firms find it harder to recruit and keep staff, and harder to make the case for new investment.
The growth already planned along the corridor depends on this line:
- Gatwick expects around 80 million passengers a year by the late 2030s, with 55% arriving by public transport.
- Croydon is targeting 10,500 new jobs, and the draft London Plan points to 800,000 more across the capital.
- Further up the line, Luton Airport is growing to 32 million passengers by 2043, and the Universal resort in Bedfordshire opens in 2031 with 8.5 million visitors and 28,000 jobs expected.
Those jobs need a railway that can get people to them. Remodelling Croydon could unlock around £5.1 billion in economic value over 20 years.
Homes and infrastructure that depend on Croydon
Councils served by the Brighton Main Line are asked to deliver around 34,000 new homes a year between them. Some of the biggest schemes are on our doorstep: more than 5,000 homes between Horsham and Crawley, 5,000 at Burgess Hill and 14,500 in Croydon.
New homes only work if the people living in them can get to work. Every new household along the line adds to the pressure on the same few tracks at Croydon. Without more capacity there, we risk building communities that are cut off from the jobs they were meant to serve.
The line matters for freight too. It supports five aggregates terminals, an expanding terminal at Salfords and freight flows between Clapham Junction and Redhill. Those flows carry the materials that build the homes and infrastructure our region needs.
The fix is ready to be designed
The Croydon Area Remodelling Scheme, known as CARS, is Network Rail’s plan to untangle the junctions. It would:
- Add around 15% more peak capacity through East Croydon;
- Make room for six extra 12-carriage fast trains;
- Rebuild East Croydon and Norwood Junction stations; and
- Allow a full recast of the timetable, with more reliable journeys across the network.
The timing matters. Network Rail already plans track and signalling renewals at Croydon. Funding the design work for CARS now, in the current rail funding period, means it can be planned alongside those renewals. That avoids paying twice and avoids years of repeated disruption. It also means the scheme is ready for a decision on building it in the next funding period, which runs from 2029 to 2034.
If the design is not funded now, CARS misses that decision, and the wait gets years longer. In September 2026, the Prime Minister told the House of Commons that the Government would look again at the scheme. Now is the moment to turn that into action.
How the APPG will take this to government
The APPG brings together MPs and Peers from every party along the corridor, from Brighton to Bedford, Peterborough and Cambridge. In May 2026, 12 MPs from four main lines met at a cross-party roundtable on CARS, and Govia Thameslink Railway and Network Rail’s Sussex route both back the case for fixing Croydon. Our job is to keep CARS in front of ministers until it is funded. Over the coming months we will:
- Press the Treasury and the Department for Transport to fund the design work now, alongside the planned renewals, so CARS is ready for the 2029 to 2034 funding period.
- Put CARS forward as a pilot for the Government’s “Rewiring the State” reforms, with national government, mayors, councils and business planning and co-funding the scheme together. This is a cross-boundary project that no single body can unblock alone.
- Seek a full debate in the House of Commons on the whole corridor before Christmas, and table an Early Day Motion so every route MP can show their support.
- Hold an evidence session with the Department for Transport, Network Rail and the Government’s devolution officials, to ask what it will take to get CARS moving.
- Bring your evidence to ministers ahead of the 2027 Spending Review, which ministers have named as the next chance to fund the scheme.
Parliament can make the case. Business can prove it.
What we are asking Gatwick Diamond businesses to do
Ministers listen to employers. A clear, visible business voice from the Gatwick Diamond is the strongest evidence we can put in front of them. We are asking every member to take three steps before the end of [month]:
- Sign the business petition. Add your organisation’s name so we can show ministers how many employers want CARS built, broken down by constituency.
- Tell us how the bottleneck affects you. Send a short note on late staff, lost meetings, recruitment or customers who cannot reach you to hello@silverstonecommunications.co.uk. Real examples from named businesses carry weight in Parliament, and with your permission we will use them in our evidence to ministers.
- Write to your MP. Ask them to back the Early Day Motion on CARS and to speak in the debate. Every MP along the line, from Brighton to Crawley and beyond, has a stake in this.
You can also add your name to the business open letter to the Transport Secretary, encourage staff who commute to join our passenger video diary, and share the campaign using #FixTheCroydonBottleneck.
The Gatwick Diamond has everything it needs to grow: the airport, the businesses, the people and the land for new homes. What it needs now is a railway that can keep up. Help us fix Croydon, Sign today.
Read more here