Award-winning actor Brian Cox has appealed to the first minister to help save the Edinburgh theatre that was "the catalyst" for his career.
The Dundee-born actor has been nominated at this year's Emmys for his role as media company mogul Logan Roy in the HBO series Succession.
He credits his early visits to the King's Theatre for inspiring a stage and screen career spanning 60 years.
The King's is facing an uncertain future because of the Covid pandemic.
It was forced to close in March while working on a £25m "planned, essential redevelopment" to make it a "modernised, more sustainable theatre".
But the project - and the 230 jobs around the city which the theatre supports - are now in doubt.
Golden Globe winner Cox has written to Nicola Sturgeon appealing for funding for Capital Theatres, the charity that operates the Festival Theatre and The Studio as well as the King's.
The 74-year-old actor told BBC Breakfast the theatre had "slipped through the cracks" for emergency funding.
Her said the closure of the King's after 104 years would be "tragic for the international community, but more tragic for the people of Edinburgh".
He said: "I used to spend a lot of time as a child with my Auntie Jean in Edinburgh and she first took me to the pantomime at the King's Theatre.
"It has always been known as the People's Theatre because it gets over 90,000 a year visiting the panto.
"The theatre has slipped through a crack for emergency funding and it doesn't receive any public funding.
"We desperately need the theatre to be given some kind of funding so that we can continue operating."
Capital Theatres say redevelopment of the King's would bring a £10m boost to the Scottish economy and £15m to the UK.
Two-thirds of the required funding is in place from a range of sources and the group is calling on the Scottish government to make up some of the shortfall.
Brian Cox said: "We have a broad-reaching programme in the community, which we do as a charity, and it's tragic if this theatre doesn't survive."