Health and safety hitches at the Rose Theatre have led to another cost over-run, landing taxpayers with a potential extra £350,000 bill.

The final price tag for the theatre refit will be £7.15m, more than £638,000 over the original budget.

The council's Liberal Democrat-run executive plans to find the extra money by raiding a £664,000 Government grant for Kingston businesses.

Councillor Howard Jones, leader of the Conservative opposition, said: "It is unfortunately the Lib Dems going back on their word.

"They said no more public money for the theatre. They can dress it up however they like."

Leader of the council Councillor Derek Osbourne blamed health and safety problems for the "relatively small over-run".

Visits from Kingston Council's own health and safety team raised concerns about wiring and doors, which added £133,000 to the cost of the refit.

Builders said the delay cost them £157,000 and the claims, filed by lead contractor Gentle Associates, will be pored over for accuracy by management consultants.

Coun Osbourne said: "Our own building control and licensing people wanted extra safety measures put in.

"That led to a delay in finishing the project which increased fixed costs of contractors working with other parts of the building."

He justified using part of a £664,000 Local Authorities Business Growth Incentive Scheme, saying the theatre was already helping businesses such as French brasserie Frère Jacques grow.

The Rose's executive director David Fletcher said: "Despite the latest news, we hope that the people in Kingston will feel a sense of pride in the fact that a magnificent theatre has been built in their community, at a far lower cost than comparable projects."

So far Kingston Theatre Limited Liability Partnership, set up to fund the theatre refit, has been loaned £5.2m, 95 per cent from the council and 5 per cent from Kingston University.

Kingston University will be asked to put its hand in its pocket again to contribute an extra £17,500 - 5 per cent.

Professor Penny Sparke, the university's pro vice-chancellor confirmed it would discuss the request for more money and make a decision.

The theatre has faced years of funding challenges since the shell was built in 2002. It was revealed in 2005 that every household in the borough would be paying up to £7 a year in council tax to help fund the theatre.

In August 2007, the council and university agreed to fund an extra £250,000 after a first set of cost over-runs.