The study by Roger Tym & Partners, Halcrow and Three Dragons for three regional assemblies would see the new town of Milton Keynes grow into a city the size of Coventry. There would also be significant regeneration of Corby and Luton.

The aim is to provide 370,000 new homes but the expansion is seen as urgent to take some of the pressure for new homes off London and the south-east. It would also go some way towards meeting the government's housing targets.

Bill Brisbane, Managing Partner at Roger Tym and Partners and Project Director of the Study, said: "If implemented, our preferred option for growth will bring substantial advantages for the Milton Keynes and South Midlands area. By concentrating growth and development in the urban areas, rural areas will be protected from sporadic development. The projected growth will potentially deliver significant economic and social benefits to the parts of the study area in need of regeneration, particularly Luton, Corby and Bedford."