East of England planners have threatened to block development in housing growth areas unless the government gives the green light to a string of long-delayed and expensive transport projects.

The East of England Regional Assembly’s planning committee has approved the inclusion of policy IMP2 in the assembly’s draft regional spatial strategy. This states that “no new housing development arising from the East of England plan will be permitted without a clear commitment by the government to priority transport schemes”.

The policy states that the Thames Gateway urban regeneration project should not proceed unless the government gives the go-ahead to the Thameslink 2000 rail scheme, the Lower Thames river crossing between Tilbury and Gravesend and new or improved access to Canvey Island.

It also states that the delivery of about 120,000 homes in the Stansted–Cambridge stretch of the M11 growth area should not go ahead unless work starts on various road schemes and phase one of the long-delayed restoration of the east–west railway line between East Anglia and Oxford. The government has commissioned a feasibility study into the rail link, but Treasury officials are understood to be worried about the cost of the scheme to the public purse.

The policy also questions the provision of an extra 21,200 dwellings near Peterborough at the northern tip of the M11 growth corridor before the A1 is widened between Brampton and Alconbury.

The assembly has also insisted that housing should be blocked unless a minimum number of jobs is created.

The policy says local councils will be obliged to hold back a share of its housing allocation until “relevant milestones” on jobs and transport projects have been met.

The public inquiry into the spatial strategy, which provides the blueprint for development across the region, is due to commence in November.

Assembly member Roger Humber, who represents the business sector, described the policy as “deeply flawed and politically motivated by the Tories”.

He warned ministers that if they accepted the proposed policy, it would be mimicked by the South-east and South-west assemblies, which are drawing up their plans.