Leader of the Tory opposition, Councillor Howard Jones said: "We think there's better things to spend £600,000 on but that's a matter of judgement. It is hard to justify. Does this mean after three years they are prepared to go even further? Derek Osbourne has dug his pit."

His fellow Tory councillor Nick Kilby said: "We were promised that their business plan was robust and would not need this support. This is a catastrophe of local government due diligence. "There's a lot of political hogwash going on and a very embarrassed leader of this council trying not to look like he has taken us into a garden of never-ending expenses."

The Tory party is likely to call in the decision if it is approved, grilling ruling councillors and officials about the decision.

Labour Councillor Steve Mama said public subsidy of the theatre was always on the cards. He said: "If they were honest enough to say so in the first place we might have had sympathy and understanding and we might even have had sympathy from rate-payers. It is a whole series of excuses without the admission they have been wrong."

Lisa Gagliani, chief executive of Kingston Chamber of Commerce, signed a petition this week with 30 other businesses supporting the Rose, and said the council deserved a pat on the back. "This is showing very clearly it believes, and I think correctly, the theatre is potentially a huge economic asset, not only to the town but the whole borough," he said.

Graham McNally, Kingston town centre manager, said the council had no choice but to support the theatre in the face of a downturn in the economy which would put businesses off supporting the Rose. He said: "It has taken a generation to get this theatre open. I know this is going to get snarled up in politics but if you view that as an investment in 155,000 living in Kingston and the social and economic investments it will bring, in the long-term it is a catalyst for change."