MP Priti Patel has called for councillors to throw out controversial plans for 28 homes in Stanway, ahead of a crunch planning committee meeting.
Developer Flagship Homes wants to build the houses in a range of sizes between Tollgate Road, Church Lane and Churchfields Avenue.
Hundreds of residents have signed a petition against the plans and believe the site should remain as a public open space.
Conservative Ms Patel, claims Colchester Council has changed the allocation of the land without consultation.
She said: "I stand alongside the hundreds of local residents who are opposed to this development and unacceptable loss of open space.
"Colchester Council has mishandled this site by changing its allocation without any public consultation.
"There are serious questions about how they have conducted themselves and the planning committee should now do the right thing and refuse this application.”
Planning officers have recommended the proposals for approval, but dozens of protestors are expected to attend the meeting on Tuesday which has been moved to Moot Hall in a bid to meet demand and three speakers will be allowed to speak both for and against the application.
Colchester Council's sustainability boss Dominic Graham (Lib Dem) said the council has taken legal advice to ensure the recommendations were sound, but the ultimate decision would be taken by the planning committee.
He said:“The report to the planning committee carefully explores many of the issues raised by Mrs Patel.
"In proceeding as it has, the council has taken independent legal advice in the form of written legal opinions which indicate that the actions we have taken are both lawful and appropriate.
“The application for 28 affordable homes – which falls within a larger site for which outline permission has been granted for a maximum 800 units – will be considered on its individual planning merits by the Planning Committee, on Tuesday, taking into account all material planning considerations."