The little-known charity desperate to buy the old Clerkenwell fire station site is planning to take its campaign all the way to Sadiq Khan.

Water Incorporated wants to move its offices from Barnet closer to central London and says the Grade-II listed building is “perfect” – but the London Fire and Emergency Planning Authority (LFEPA) says it’s no longer on the market.

The charity is backed by Dutch benefactor Wolf Barleugh – a former solicitor with a love of historic buildings – and claims it would have no problem stumping up the millions required for the Roseberry Avenue station, which was the oldest in the UK before Boris Johnson named it as one of 10 to be shut in 2014.

And after being repeatedly snubbed, bosses have now asked City Hall for permission to hand Sadiq Khan a petition calling on him to re-open the bidding process.

It contains 1,100 signatures from neighbours in Exmouth Market, Chapel Market and St John Street.

The street campaigning was led by trustee Peter Ulrich, who said just uttering the words “Clerkenwell fire station” caught people’s attention.

He said: “People would go and fetch friends and relatives to sign and we had market traders sending customers over.

“There can be no doubt there is huge support for the station to have a new role in the heart of the community rather than becoming another faceless block of luxury flats.”

The future of the station has been a major talking point since it closed, not least because taxpayers have shelled out more than £264,000 paying for maintenance, security and utilities while it sits empty, as revealed by the Gazette last year.

The charity has vowed to meet all the criteria of Islington Council’s planning brief for the site. It says it will preserve the building, keep it open to the public and open a museum celebrating the station.

The flats above would be student accommodation and the charity said it would also build affordable housing at the back.

But despite all this, Peter says LFEPA even banned him from asking a question at a City Hall meeting.

A City Hall spokesman said the mayor was determined to get to grips with the housing crisis and develop sites owned by the GLA.

He said: “LFEPA is considering how best to dispose of a number of vacant sites, including the former Clerkenwell Fire Station, in line with the mayor’s commitment to delivering the genuinely affordable homes Londoners need.”