Plans to give a new school a 125-year lease on a public park have been given the green light, despite one of the councillors approving them branding the location "ridiculous".
However, campaigners opposing the loss of green land at Brent Lea Recreation Ground, in Brentford, claim a covenant could yet scupper the school's plans.
At a cabinet meeting on Tuesday (June 16), councillors unanimously approved proposals to give the school's founders a lengthy lease at the site, potentially paving the way for a permanent planning application which would take up about a third of the grounds.
They said they were left with little choice as the council has a statutory duty to ensure there are enough school places, and there would be a shortfall without the new school.
However, they said they would make it their "mission" to identify a more suitable alternative site in coming months, despite previous searches having proved fruitless.
Councillor Theo Dennison, one of three cabinet members representing Syon ward, in which the recreation ground is located, said: "I have yet to find anybody who thinks this is a suitable site. I think it's a ridiculous site to consider putting a school on...
"It's our mission over the next few months and years to identify a suitable alternative permanent site for this school."
Those alternative sites could include Acton Lodge, a former day centre for people with disabilities, or the bus garage at Commerce Road, which had originally been earmarked as the school's home.
Council leader Steve Curran said a review was under way into the future use of Acton Lodge.
Bus operator Metroline, which leases the land in Commerce Road, this week said it had found a potential alternative site for a garage and discussions were ongoing regarding a move.
Meanwhile, members of the campaign group Save Our Rec (SOR) said a covenant limiting the use of the parkland to recreational purposes could yet stop the school from opening there.
They say the covenant means freeholders on the neighbouring Brent Lea council estate, who bought their homes under the Right to Buy scheme, must give permission for the land to be built upon.
Hounslow Council officers claim the Duke of Northumberland, owner of the neighbouring Syon Park estate, who is also a beneficiary of such a covenant, has indicated he would give consent.
But Brent Lea resident Jack Butcher said he and two other freeholders there planned to reject any such request and were taking legal advice on the matter.
Although the cabinet approved plans on Tuesday to grant the lease in principle, it still has to be personally signed off by Mr Curran.
Should he put pen to paper, the school would be awarded the land in return for a peppercorn rent and £60,000 upfront to pay for improvements to the remainder of the park, which would stay open to the public.