Countryside campaigners fear Oxford will become a sprawling metropolis like Los Angeles if their battle to protect the Green Belt is lost.
Large swathes of the city's "green lung" from Kidlington in the north to land off Grenoble Road near Greater Leys to the south is under threat from developers.
Deputy Prime Minister John Prescott is allowing 2,500 acres of Green Belt land to be built on each year and has yet to approve the South East Plan, a document that forbids building on Oxford's Green Belt until 2026. Green lobbyists think that with pressure to build 2,360 houses in Oxfordshire a year, it is only a matter of time before the land is raided and could be gone within 15 to 20 years.
Today, Adam Boddington, of the Oxfordshire branch of the Campaign for the Protection of Rural England, warned of a new battle between green space and concrete. Mr Boddington said: "We are trying to stop places like Oxford becoming like Los Angeles where you can drive for 30 miles before you see any greenery at all - it's destroyed the character of many communities over there. Ultimately, if building south of Oxford goes ahead then there is every chance the city will join Abingdon and become one large conurbation - which will not do anything for Oxford, let alone the countryside. The Green Belt is under threat. There are colleges, the city council and industrial firms that would like to build there but it will spread Oxford southwards, create a new skyline and a lot more traffic. We could see this urban sprawl within 10 to 15 years."
Labour's Oxford East MP Andrew Smith has backed the city council's battle for an urban extension and is lobbying for an urgent review of the Green Belt to allow development there. Meanwhile, Oxfordshire County Council leader and chairman of the South East England Regional Assembly, Keith Mitchell, has vowed to protect the countryside.
City councillor Ed Turner, executive member for strategic planning, housing and economic development, said: "It's about safeguarding spaces for future generations, but at the same time I am thinking about future generations of Oxonians. I don't want them to only be able to afford a house at £250,000 a pop. We want a review of the Green Belt and to expand outwards to build an urban extension. The CPRE is condemning people in the city to homelessness."
Oxford's current housebuilding rate is poor. Some 1,750 are needed every year to keep pace with demand, but just a few hundred are being built. Mr Boddington added: "Oxford is a very crowded city and we need to concentrate more on developing county towns."