Bids to purchase the old Hampstead police station must be submitted to estate agents Cushman Wakefield by July 8.

The future of the Rosslyn Hill property has been up in the air since the Department for Education decided to sell it, having failed to get planning permission to use it as a home for Abacus Belsize Primary.

Local figures have spoken of hope for the property to remain at least partially open to the public, and Hampstead campaigner Jessica Learmond-Criqui is even hoping to return a police presence to Rosslyn Hill.

She is trying to fundraising so investors can buy the old cottage on the site, which, along with the police station and its magistrates' court, is for sale.

Jessica is hoping to raise a £1.29m offer for the cottage, and then to fund its refurbishment. It is not known whether a bid for only part of the property would succeed. The whole site is been marketed for slightly more than £10m – less than the £14m the DfE paid for it in 2014.

Jessica said some investors have already pledged money – depending on terms – and the idea would be to safeguard a police base in Hampstead for the next five years and "buy time" for the community.

She said she believes offering the cottage rent-free to the Met would be an attractive prospect.

Jessica would like to see officers for six safer neighbourhood policing teams based there – from Hampstead Town, Frognal and Fitzjohn's Belsize, Gospel Oak and Swiss Cottage wards.

"It's a tall order but I'm never discouraged by a challenge," she said. "We've raised around £75,000 to £175,000, depending on the terms.

"The idea will be to treat it as a commercial property, to have it for five years which gives us the time to keep that space for the longer term. It's really the last chance for a lifetime."

Other community figures have previously called for it to remain at least partially open to the public.

David Castle from the Heath and Hampstead Society's planning sub-committee said he hoped "at least the lower floor could be used for some public use", while former local councillor Linda Chung said it would be "disastrous" for the site to become luxury housing.

Photographer Jill Furmanovsky floated turning the building into a "rock'n'roll museum".

The Met Police has not responded to a request to comment.