A councillor has claimed “not a coffee bean” of funding has been secured towards a £30million revamp of Lynn’s Guildhall theatre.

Cllr Alun Ryves has warned that West Norfolk Council has embarked down a “road of doom” after committing to borrow up to £16million to overhaul the venue.

The independent member, who supported the proposal when it was approved last summer, said he now fears the authority has been left exposed as promised private investment is yet to be secured.

“This is an example of the desire by councillors to leave a legacy project, regardless of the costs,” he said.

“Councillors were persuaded to embark on this road of doom by repeated assertions that there was a tsunami of money ‘waiting in the wings’, ready to be thrown at the project, awaiting only the agreement if the council was to proceed.

“Guess what – not a coffee bean has been received, beyond a roof repair grant that was unrelated to this daft project.”

The restoration project has proved contentious since it was first proposed.

The Guildhall is regarded as the oldest working theatre in the country and is one of the few existing venues able to claim that Shakespeare almost certainly performed there.

The renovation scheme was initially expected to cost around £12million and was due to be supported by £9million from the Government’s Town Deal programme.

But rising construction costs, additional expenses due to medieval architectural discoveries and a growing ambition for the scheme have meant the overall price tag has more than doubled.

The borough council had hoped that the links to Shakespeare would entice wealthy philanthropists to help fund the scheme, but Cllr Ryves claimed these pledges are yet to materialise.

He described the decision to take on up to £15million of debt as “grossly irresponsible”, adding that the financial pressure had “squeezed out other more worthy projects such as the renewal of the St James swimming pool”.

The council has argued the redevelopment will safeguard the historic building, expand its cultural use and deliver long-term economic and educational benefits.

A spokesman for the authority said: “The Guildhall and Creative Hub project will see the medieval venue, empty buildings and courtyards revived as inspiring, welcoming spaces for everyone, creating a heritage destination, new food and drink offer, home for creative industries and year-round programme of performances, events and education programmes.

“Our exciting vision for this beloved and unique venue is a year-round local, regional and international destination for heritage, arts, creativity and theatre, which will bring profound opportunities to all our residents, young people, visitors, economy and the creative scene.

“Last year, full council agreed to earmark the funding required to allow the main works to get underway in the autumn, and officers have continued to actively explore significant external investment opportunities, to add to £10.1million already committed from the Government’s Town Deal for Lynn.

“Since then, the council has secured a generous grant of over £720,000 from Historic England’s Heritage at Risk Capital Fund towards the roof restoration and a linked project to date the historic timbers on the site.

“The Guildhall has also been identified as a priority project within the Pride in Place programme, which will see up to £20million of Government investment in Lynn over the next decade.

“Understandably, securing significant third-party funding takes time, but we have already had crucial, welcome support from Historic England and continue to actively explore funding opportunities, locally, nationally and internationally, from a range of potential sources.”

Building works are now under way with scaffolding surrounding the theatre, and plans progressing for an immersive visitor experience.

Organisers are hopeful the entire project will be completed by 2028.