The Government could be called in to rule on the redevelopment of the former US airbase at Upper Heyford.
The North Oxfordshire Consortium lodged plans for Heyford Park in November, but has yet to hear from Cherwell District Council.
It wants to build a housing estate, a school, shops, and business units, which could create more than 1,000 jobs.
The US Air Force moved out in 1993 and three years later it was bought by the consortium for £24.4m. However, the council has yet to rule on the scheme, despite reaching the limit of the four months it has to make a decision.
The developers have spent 11 years trying to push through proposals and may now lodge an appeal with the Government's Planning Inspectorate.
The delay has also sparked fears for jobs if firms on the site move out, with the South East of England Development Agency also calling for a quick decision.
A council spokesman said: "The council has not unduly delayed consideration of the application. It has undertaken the full assessment and consultation process that it considers necessary to make a sound decision on a major scheme. Economic regeneration is one of our priorities."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules hereComments are closed on this article