TV stars Richard Briers and Robert Powell joined theatre-goers in celebrating Alan Ayckbourn's 70th "un-birthday" when the playwright appeared at a champagne festival gala at The Royal & Derngate on Sunday.

The writer was at the venue to launch an Ayckbourn season which is going to be playing on the Royal stage this spring and summer.

It was also a chance to celebrate the life and career of one of Britain's most prolific and respected living authors.

In a 90-minute show actors who had worked with the Scarborough-based dramatist presented a series of sketches from some of his back catalogue.

Special guests Briers and Powell took turns on stage to offer their plaudits on the writer's remarkable career and brought the house down when they admitted that they had scarcely worked with their friend and colleague.

Robert Powell, now starring in Holby City, said he was forced to scratch a living back in the 1960s when he was a struggling young actor. He said: "I first worked for Alan in 1967 – and I last worked for him in 1967!

"I'm still waiting, Alan, 42 years! I appeared in one performance and the play has never been performed anywhere in the known universe since!

"There are a lot of writers in the world but none better than him."

Richard Briers, who at 75 is still acting, said he had never worked with Ayckbourn but he sympathised with his friend reaching 70.

"It's not easy. Someone stopped me and said:' You were a marvellous – in your day!"

The playwright, whose black comedy Just Between Ourselves, is running at the Royal until June 13, praised the collaboration of casts and companies in making his plays so successful.

"We (writers) get the ideas but it is they who make them fly," he admitted.

The writer, whose actual birthday was in April, added: "This is one of the nicest un-birthdays of my life. I might hopefully stick around until I am 80."

The Ayckbourn season continues with Private Fears in Public Places from June 22-July 11; The Revengers' Comedies from July 7-11; Orvin Champion of Champions from July 16-18 and Man of the Moment from July 27 to August 15.