A hi-fi firm says security fears led it to jump the gun on planning permission for a new store in Bath.

A heritage campaign group in the city is calling on planners to take enforcement action against hi-fi and TV store chain Richer Sounds, which has opened without formal planning consent.

The store opened in the former Porter Butt pub in London Road in mid-August, despite not having listed building consent or permission to put up signs.

Before the firm moved in, the building had been occupied by squatters.

The company has defended its decision to open, saying the threat of break-ins had prompted it to make alterations. It said all its actions had been done following talks with council planners.

But the Bath Heritage Watchdog group, which monitors changes to the city's listed buildings, wants Bath and North East Somerset Council to take a harder line with the retailer.

The organisation said on its website: "The last we heard ... was that the work taking place was essential repairs, authorised by conservation officers, to replace rotted timbers in floors and roof supports which currently make the building dangerous. Opening a retail outlet without planning permission is not what is usually regarded as essential repairs.

"Unless enforcement action is taken over this particular abuse of planning legislation, it will set a precedent for any other premises in B&NES. Attempting to enforce any similar situations in the future will leave the council open to accusations of favouritism or bias."

A spokeswoman for Richer Sounds, which said the company enjoyed "good working relationships" with planning authorities across the country, claimed the firm's hand had been forced by a series of attempted break-ins at the building.

"Squatters illegally occupied the premises earlier in the year and we subsequently had four break-in attempts following their eviction," she said. "After careful consideration and taking advice, Richer Sounds took the view that the property was under constant risk while standing vacant and so we undertook superficial repairs and redecoration to enable us to begin trading.

"We have held lengthy discussions with local authority officers on the works that have required consent, pending formal agreement.

"Richer Sounds has strived to protect this site against vandalism and disrepair and has done so with a constant and respectful dialogue with local conservation and planning, amending designs where necessary."

A spokesman for B&NES said a listed building application for the site was currently under consideration "following extensive negotiations" while an advertisement consent application had been submitted but was awaiting validation.

"No enforcement action will be taken while the necessary applications are under consideration, as the council has to be seen to be giving the applicant a fair chance to regularise the works," he said.

"Only in the event of permissions not being granted would enforcement action proceed."