The ambition to turn the Oxford–Cambridge corridor into “Europe’s Silicon Valley” is in danger of stalling unless the government accelerates delivery of long-promised infrastructure, business leaders have warned.
A coalition of major companies, universities and investors has written to Rachel Reeves urging faster progress on transport and planning commitments for the so-called OxCam supercluster, amid growing concern that delays to the East West Rail project are undermining investor confidence.
The warning comes in a report from the Oxford-Cambridge Supercluster, backed by 46 organisations including AstraZeneca, GSK, Airbus and the Ellison Institute of Technology Oxford, founded by US tech billionaire Larry Ellison.
The corridor has been championed by the chancellor as a cornerstone of Labour’s growth strategy, with ministers promising to unlock a projected £78bn boost to the UK economy by 2035 through science, technology and life sciences expansion.
However, the report warns that uncertainty over infrastructure delivery — particularly the East West Rail (EWR) line — risks blunting that potential.
The East West Rail scheme, designed to connect Oxford and Cambridge via Milton Keynes and Bedford, is widely seen as critical to turning the region into a single integrated labour and innovation market.
But concerns are mounting that the project is slipping behind schedule. Industry leaders fear the required development consent order may not be submitted until 2027, meaning final approval could fall beyond the current parliament — putting the government’s 2035 operational target at risk.
Andy Williams, chair of the Oxford-Cambridge Supercluster board and a former senior AstraZeneca executive, said the lack of certainty was already harming confidence.
“Without clarity and pace, we risk killing investor confidence,” he said, warning that trains may not run the full route by 2035 unless action is taken quickly.
The corridor has regained political momentum after being deprioritised under Boris Johnson’s government, when regional “levelling up” became the focus. Business leaders have welcomed Labour’s renewed attention, but say ambition must now be matched by execution.
While the government committed £2.5bn in June’s spending review to progress East West Rail, the report argues that funding alone is not enough without a clear, region-wide delivery plan.
The government has taken some steps, including approving the reopening of the Cowley branch line in Oxford and appointing Lord Vallance as the corridor’s growth champion. Ministers have also promised a more detailed plan this year.
But the report calls for stronger governance across the entire region, alongside an overarching spatial strategy setting out where housing, laboratories and commercial space will be prioritised — and how supporting infrastructure will be delivered.
The report, produced with the Centre for Business Research at the University of Cambridge, shows that economic growth is already spreading beyond Oxford and Cambridge into places such as Milton Keynes and Stevenage, home to a major GSK research site.
The corridor now hosts around 3,000 knowledge-intensive firms, employing 152,000 people and generating £45bn in annual revenues. Employment growth has outpaced the UK average over the past decade.
Shaun Grady, chair of AstraZeneca UK, said East West Rail was “vital infrastructure” needed to connect campuses, labs and cities into a single talent market and ensure scientific advances translate into economic growth more quickly.
Nick Pettit, senior partner at property adviser Bidwells, added that the rail link was the “missing piece” and said the government must provide planning certainty and accelerate delivery of housing and workspace along the route.
A Department for Transport spokesperson said East West Rail remained a “catalyst for growth”, adding that officials were examining how recent planning reforms could be used to deliver benefits sooner.
If completed, the line is expected to cut journey times between Oxford and Cambridge from around three hours to just over 90 minutes — a transformation businesses say is essential if the UK is serious about building a globally competitive innovation corridor.
