“We will probably have to downsize or unfortunately the club will have to close,” the chairman of City of London Football Club warned.

Eamon Gately says plans to develop Finsbury Leisure Center are “not suitable for the community”.

Islington Council plans to build 198 homes in this area. The plans, if approved, would see the four football fields be reduced in size and placed on the roof of a new leisure centre.

The council said it had “carefully considered” the layout of the planned buildings to minimize the impact on neighbours.

Mr Gately told BBC London: “This will have a huge impact on the football club.

“Their proposal is for a two to three year project to construct the building.

“They have no idea where to put these kids into this.

“We will probably have to downsize, or unfortunately the club will have to withdraw.

“Where are these kids going? They will join another gang. They will no longer be a football gang, but a street gang.”

Former football player and football coach Les Ferdinand showed his support for the club with a visit on Wednesday.

“I know what this means to the community and other communities like this,” he said.

“I understand we need social housing, we need more housing.

“But at the same time, if you bring in 100 more families, how many more children will you have?

“I hope the council listens.”

Eva Guerra, of EC1VOICES, the campaign group trying to save the grounds, said: “I think there is a real divide between what the council thinks the community needs and what the community and people living in this area think and know they need.

“We are all united in the need to protect this area.

“This place is very special, a rare oasis of greenery in a densely populated part of the country.

“It’s about a space for children and young people; there’s something really unique here.”

An Islington Council spokesman said: “The new 5/6-seater rooftop football pitches will be of high quality, built to FA standard specifications and will include a spectator area.

“Subject to planning permission, this project will deliver 100 new council homes, 98 homes for sale to help pay for it, an NHS GP medical center and new leisure facilities. Residents are strongly encouraged to send their comments on the planning application to Islington on the council’s website site.”