If the Playhouse cannot stage the shows and alternative venues cannot be found, Glasgow could take part of the Edinburgh International Festival for the first time since the arts gathering started in 1947.
Work on the pounds 2m first stage of a pounds 4m renovation was nearing completion when arson destroyed parts of the rear entrance to the Playhouse on Wednesday and caused smoke damage to the interior. A gala performance tomorrow featuring the singer, Michael Ball, has been rescheduled. The Cameron Mackintosh organisation is promoting the gala and a season of the musical, Les Miserables, beginning on 16 September. Advance bookings run into millions of pounds and the Playhouse's owner, Apollo Leisure UK Limited, has told Cameron Mackintosh it envisages 'no problems'.
The same reassurance has not been given to the festival, which has 11 performances, involving two opera companies and one dance company, at the Playhouse. If sold out, takings would have been pounds 450,000. Joanna Baker, festival marketing director, said fire officials had told her the theatre was safe. 'So we've said we want to go ahead.'
A major loss would be receipts from the Mark Morris Dance Company, from New York, one of the financial successes at last year's festival. 'They telephoned to ask if they should come. We told them 'Get on that plane',' Ms Baker said. Just over 12,000 seats have been sold for Mark Morris, the Canadian Opera Company and the Welsh National Opera.
Lothian and Borders Fire Department said the blaze started outside the theatre's loading bay. Materials, including paint from the refurbishing work, were stored outside a temporary corrugated structure joining the main theatre. Fire officer Derek Bannan said: 'Rubbish was maliciously set alight. There is extensive smoke damage . . . But the theatre itself is safe.'
A spokeswoman for the Playhouse said that renovation work was 'almost complete. It involved 10 or 11 main contractors. We were on schedule'.
Nearly every theatre is taken for the official festival or the extensive Fringe and rivalry between Glasgow and Edinburgh has meant that Glasgow has never staged a festival event.
However, the Theatre Royal in Glasgow has been unofficially contacted. Peter Helps, the general manager, said: 'We were approached and have informed the festival that we do have available dates to suit them.'