Haringey’s council leader has defended a £35.9 million deal with a local secondary school following criticism of the plans by former cabinet members.

The proposal would provide a new sixth-form building for Fortismere School in Muswell Hill and allow the local authority to build homes on land currently owned by the secondary school.

Haringey’s Labour administration was elected on a pledge to provide 1,000 new council-owned homes by 2022 – and the development would help it to reach that target.

Funding for the deal was included in the 2019-20 budget paper that was approved by cabinet on December 11.

Haringey Council claims the proposed tie-up would be self-financing and all the investment would be recouped through home sales.

But the plans have come under scrutiny after two cabinet members who were sacked by council leader Cllr Joseph Ejiofor on New Year’s Eve hinted their opposition to the proposals may have led to their departure.

In a statement emailed to Labour councillors following her sacking, Cllr Zena Brabazon said she thought her opposition to the plans was “the real reason I have been removed from cabinet”.

Cllr Brabazon warned the proposed deal would be “hugely risky” and claimed it was “slipped into the capital budget at the last moment without any prior cabinet discussion [and] with only a brief background general paper”.

Cllr Peray Ahmet, former cabinet member for adults and health, also said she had raised “strong concerns about the Fortismere capital programme” in an email to Labour colleagues.

Council leader Cllr Joseph Ejiofor was a governor of Fortismere School from June 2016 until May last year, and he is one of four councillors who currently have children at the school.

He emailed Labour Party members last week stressing plans were in the early stages of development and would not go ahead unless the council “gets its money back in full”.

Cllr Ejiofor added that the £35.9 million was included in the council’s capital budget for 2019-20 because “there was a possibility that a proposal might be developed in this period”.

Cllr Ejiofor said: “Every member of the cabinet at that time knew the full reality of the relevance that this line item had, and how far the project was from a report coming to cabinet.

“They are also aware that the full options appraisal for all school repairs is due in the summer.

“Every cabinet member was clear that, if the Fortismere project was to be approved, it would not take a single penny away from the allocation of capital available to repair Haringey schools.”

Fortismere School’s co-headteachers Jo Davey and Zoe Judge, and chair of governors Mark Chapman, set out the case for a new sixth form in a letter sent out to “friends and neighbours” in May last year.

The letter states that the current “Victorian/Edwardian building” is “dark, smelly and dank” and “literally falling apart”, with maintenance costing “tens of thousands every year”.

Adding that it would cost an estimated £20 million to build new facilities, the letter revealed a partnership with the council was being explored “out of necessity” because other means of raising funds had not been successful.

Sakina Chenot, Haringey Liberal Democrat spokesperson on schools, acknowledged the sixth form needed “major investment” but said the council should put forward a “fully costed business case”.

She added: “The council has confirmed that the redevelopment is supposed to be self-financing, and last month we made a formal request to the council for the financial modelling for the project. We have yet to receive a satisfactory answer.”

Haringey Council said the plans for Fortismere School would be subject to a feasibility study and risk assessment before being considered by the cabinet.

Cllr Noah Tucker, the council’s cabinet member for corporate services and insourcing, said: “This proposal was initially raised to the council in 2015 and remains at an early, exploratory stage, with no firm decision having yet been taken.

“It would aim to be a self-funding partnership to replace existing school facilities and deliver new homes, including council homes.

“If, following our feasibility study, the council decides to support the project, there will be a number of steps to take before this proposal can progress, including a cabinet decision on the project.

“I want to be clear that we will only consider a proposal that is value for money for the council, fits in with our plans for the wider Haringey school estate, and is one that will genuinely provide social benefit for the community.”