Kidman's Blue Room co-star Iain Glen is the artistic director's brother

Spokeswoman Nicola Young said: "We got a phone call from Mrs Kidman in Australia saying she and Tom would be delighted to get involved with the theatre and lend their names to the campaign.

"We are thrilled that despite their busy schedules they were prepared to help us.

"Nicole started out in theatres in Australia and she recognises how important they are to communities and to the acting profession."

The theatre's artistic director Hamish Glen asked the couple to get involved after Kidman starred alongside his brother Iain Glen in David Hare's play The Blue Room in London and New York.

He met the couple after seeing the play, which caused a sensation when it was revealed Kidman would appear naked.

Young said: "Hamish got on very well with Nicole and Tom and he decided to write to them to see if they'd help out."

In 1995 and 1996, the theatre was the first venue outside the Scottish capital to take part in the Edinburgh Fringe. It is also home to the Scottish Dance Theatre.