A fundraiser will have to find £2.9million to help fit out a women’s centre on the former site of Europe’s largest women’s prison – whose famous inmates included Ruth Ellis and Rosemary West.

Developers Peabody agreed to appoint a fundraiser to find the money for the Women’s Building after it said it could not afford the cost as part of its £400m redevelopment.

The council’s executive has agreed to underwrite the cost from the community infrastructure levy that Peabody is paying towards the scheme – if it can prove it has made every effort to raise the money elsewhere.

The scheme will transform the site into 985 homes, a park and a Women’s Building to help women who have been in trouble with the law.

The deal hammered out between the council and Peabody, which bought the site for £82m from the Ministry of Justice, includes an “unprecedented” mid-stage viability review.

The overall scheme was approved by Islington’s planning committee last month.

If the scheme shows a surplus, it will be used to either convert the proposed shared ownership units into London Living Rent units, to kit out and run the Women’s Building, or to change additional market housing units to social rent.

Islington’s planning committee wanted to know how much surplus Peabody expected to make. If there is no deficit, the housing association said it anticipated a 17.5 per cent surplus.

The agreements are crucial for Peabody as London Mayor Sadiq Khan will now look at the scheme and decide whether to approve or reject it.

Peabody said it can get started on the multi-million pound building project this year if Khan approves the plan.

Project manager Tom Williamson told the planning committee that further delays would put grant funding, which supports the extra affordable housing, “at significant risk”.

Campaigner Niki Gibbs said the community wants to buy a building earmarked for private homes from Peabody to create a Women’s Centre.

It follows concerns that the Women’s Building included in the plans is too small to offer therapy and support.

Cllr Paul Convery said the planning process has taken a “gruelling” three years and paid tribute to campaigners who fought for changes.