Campaigners have stepped up their bid to save a theatre as a live performance venue by launching an urgent funding appeal.

The Our Brighton Hippodrome campaigners have launched a fighting fund appeal to raise £15,000 in 20 days to help finance their battle to revive the 117-year-old building. Organisers said the Hope for Hippodrome fund will help to pay for expected legal costs.

The group is lobbying the Secretary of State to call in the proposal to transform the venue in Middle Street, Brighton, into an eight-screen cinema and four restaurants.

Brighton and Hove City Council’s planning committee voted last week to approve the £17.5 million plans that will see much of the auditorium’s prized plasterwork and decor retained and refurbished.

But objections from the Victorian Society to the plans meant the council referred the decision to the Government, which will now decide in the upcoming weeks whether the application should be decided by a public inquiry.

The team behind the plans say the renovation is reversible, allowing the site to be converted back to a theatre at a later date.

Council officers told last week’s meeting that the cinema renovation would mean up to 60% of the work needed to restore the live performance capability would be carried out.

West End shows Our Brighton Hippodrome campaigners are working on plans for it to be used as a 1,550-seater site capable of hosting theatrical performances, including West End shows. They say a restored Brighton Hippodrome, together with the Dome Concert Hall, the Theatre Royal and the Brighton Centre, would make the city a contender for the title of “entertainment capital of Great Britain”.

A petition launched last week calling on Local Government Minister Eric Pickles and Planning Minister Brandon Lewis to call in the decision was submitted after gaining more than 1,700 signatures.

Campaign member David Fisher said the group is working on a viability study for its proposals and were working on a business plan with the country’s biggest theatre organisation, Ambassador Theatre Group.

He added: “We are optimistic that the Secretary of State will call the application in. This will give us a couple more months. We are going to need a fighting fund, particularly for legal representation.

“The money started rolling in as soon as people knew about the fund, which is encouraging.”

Our Brighton Hippodrome supporters are being asked to donate a minimum of £2 to the fighting fund.

Payments can be made over the counter at any Lloyds Bank. People can also transfer money online using sort code 30 84 41 and the Our Brighton Hippodrome account number 44235460.