A campaign is brewing to protect one of Hampstead’s best-loved watering holes amid fears a refurbishment could wreck its historic character.

Residents are rallying after learning Fuller’s brewery intends to undertake work at the Grade II-listed Holly Bush, in Hollymount, which it bought in 2010.

Rumours abound that Fuller’s is planning a major overhaul to transform the 200-year-old pub into a restaurant in all but name, with little room for non-diners. Fuller’s has insisted it “does not operate restaurants”, but that has not appeased residents who are urging the brewery not to alter the pub’s historic character.

Jessica Learmond-Criqui, a solicitor who spearheads the Hampstead Shops Campaign, said: “This is one of the last bastions of traditional pub life in this corner of the world and people really don’t want it to change.

“My information was that Fuller’s are going to close the pub, refurbish and then reopen it as a restaurant.

“They have since said they don’t run restaurants, but even if they are increasing the number of tables and dining space, then it becomes a very different animal.”

Fuller’s says it is planning “some work to the kitchen” but that The Holly Bush will “remain a characterful pub which Hampstead can be proud of”.

But residents are convinced the changes could see much of the main pub and the upstairs function room become dining space.

“We’re asking them to tell us exactly what they’re planning, because there are conflicting messages,” added Ms Learmond-Criqui, who lives in Redington Road, Hampstead.

“What we’re hearing privately and what they’re saying publicly, the two things don’t tally.”

Fuller’s has also been criticised for modifications made last year without the proper permission.

A new ventilation unit was installed in August without listed building consent. Camden Council inspected following complaints and found a breach of planning permission. The council is now working with the pub to resolve the matter.

Alastair Munro, 44, a tax advisor who lives two doors away in Hollymount, said the unit is pumping out foul-smelling fumes that mean he cannot keep his window open.

He added: “We’re all worried that the character of the pub is going to be destroyed. The pipework and extractor was not given planning permission, and having seen how badly they handled that, we worry they’re going to make a even bigger mess of the refurbishment.”

Stiofan Brady, operations manager for the pub, said: “We are undertaking some work to allow the pub to cater for all its customers a little better, including some work to the kitchen.

“Fuller’s does not operate restaurants. We run pubs that concentrate on outstanding ales and beers, great wines and delicious fresh food.”