Former Mayor of Bath and council chairman Bryan Chalker has quit the Conservative Party to become an independent councillor.
The retired policeman says he is fed up with his party at both a local and national level.
Mr Chalker's defection means that his Lambridge ward which elected two Tories - him and Dave Laming - at the last election is now represented by two independents, and takes the number of independents on B&NES to five.
Mr Chalker, who was first elected in 2003, said: "In recent years I have become increasingly disenchanted with the back-stabbing, pettiness and hypocrisy of local politics and now wish to serve my Lambridge constituents as an independent ward councillor."
The keen musician said the final straw had been the future of the Americana music festival, which he organises, saying there had been a "total lack of support" from his own party.
"I spent more than six years helping to organise this unique and popular event and took no fee or expenses during this time. I am now faced with raising £25,000 in sponsorship money to fund a third Americana Festival in 2013, or it will be abandoned. As music has played a major role in my life for more than 50 years, I refuse to throw in the towel without a fight."
He also objected to the national Conservative policy priority of installing police and crime commissioners.
"I am also appalled at the sheer folly of squandering in excess of £70 million on the recent police commissioners' campaign, when what we really need is a visible police presence on our streets to combat crime and anti-social behaviour."
He said he hoped to be allowed to continue being member champion for heritage and historic environment.
"I do what I do because Bath is my favourite city and I cannot imagine living anywhere else. I love the city's glorious past – Roman, Georgian and industrial."
He added: "I should like to take this opportunity of thanking my Conservative colleagues for their friendship over the past decade and hope it will continue without any bitterness – but I cannot be alone in losing all faith in David Cameron."
Mr Laming and another then Tory, Malcolm Lees (Weston), became independents earlier this year. The others on B&NES are June Player (Westmoreland) and Doug Deacon (Timsbury).
The independent group - which has voted en bloc and differently in the past - is now the same size as the Labour presence on B&NES.
