The fate of a park in Brentford and the new primary school hoping to build there will be decided at a meeting on Tuesday (June 16).
Floreat Brentford already has temporary planning permission to open in Brent Lea Recreation Ground, in London Road, this September, and remain there for up to two years.
The plans have proved hugely controversial, with local residents joining forces with Hounslow Green Party and Hounslow Friends of the Earth to launch the campaign group Save Our Rec.
However, council officers and Floreat Education, which has 30 children due to start at the school this autumn, have both pointed out the demand for school places locally and said exhaustive searches have not turned up any alternative sites.
Such is the strength of feeling locally that the cabinet meeting, which will start at 7pm, has been moved to the Lampton Park Conference Centre, downstairs at the Civic Centre, in Lampton Road, Hounslow, to accommodate a bigger audience.
Cabinet meetings are often snappy affairs, with councillors from the ruling administration quickly approving decisions, but this one is expected to be a different affair, with members of the public having been promised the chance to get involved.
The decision comes as politicians are gearing up for the Brentford by-election on July 9, and the Conservative, Green and Liberal Democrat candidates have all expressed their opposition to plans for the school to be built on the park site.
New Brentford & Isleworth MP Ruth Cadbury, whose resignation from the council sparked the by-election, this week said it was a difficult matter.
She accused her predecessor Mary Macleod and London Mayor Boris Johnson of failing to persuade Transport for London (TfL) to free up the bus garage site at Commerce Road, used by Metroline, which had been earmarked for the school.
"Replacing the buses with a school was a key element in the planning permission granted by Hounslow Council in March 2012 for the canal-side development, as the council predicted the need for a new primary school in Brentford," she said.
She described the recreation as a "green lung" valued by local people but said 30 families whose children were waiting to start school this autumn would have to look elsewhere if the school could not open there.
"Time is not on Hounslow Cabinet's side. If they can't reject the proposals tonight, the cabinet must guarantee, as a minimum, that the majority of the open space is returned to open space immediately the permanent building is erected, and that the open space be maintained in perpetuity as a good quality public park," she said.
Ms Macleod, MP for the area from 2010-2015, criticised the council for what she said was a "lack of energy and commitment" on the issue.
"Brentford needs someone like Patrick [Patrick Barr, Conservative candidate in the Brentford by-election] to challenge the council on their lack of energy and commitment on this issue," she said.
"As MP I fought hard to deliver a new school site on Commerce Road but now the council seem to be willing to throw it all away.
"They should at least have the decency to tell local residents the truth about their plans for Commerce Road.
"I hope that the new MP, Ruth Cadbury, will not be afraid to challenge her former colleagues on such an important matter for the future of Brentford."