The construction of a new performing arts centre in Leicester is to go ahead, despite its budget nearly doubling.

Leicester Council this week decided to move ahead with the project, whose budget has gone from £26m in 2002 to £48m. The move ensures the existing role of QS Turner & Townsend as cost consultant on the project, which the firm has held since December 2002.

The council decided to back the project, designed by US architect Rafael Viñoly, because of its importance to the regeneration of the city. It was due to sign a fixed-price contract with contractor Bovis Lend Lease on the project at the end of this week.

Liberal Democrat council leader Roger Blackmore said: “This is a major step for regeneration of the city and the cultural quarter. We have managed to negotiate a contract where 87% of costs are fixed, to prevent costs rising as with the Scottish Parliament building.”

Theatre supporters welcomed the news. Anthony Lawton, chair of the theatre trust, which will run the premises, said: “We can now move forward with confidence to deliver a theatre of national importance, to be enjoyed by city- and county-wide audiences.”

Work is due to start on the complex next month and is due to be handed over late 2007. It will replace the Haymarket Theatre and provide facilities to incorporate work presented at the Phoenix Arts Centre.