Veteran actor Brian Blessed collapsed on stage while playing King Lear, but returned after 20 minutes to finish the show.

Blessed, 78, had begun to deliver his opening lines in the Shakespearean tragedy when he apparently fainted and fell from a raised platform.

Daily Mail critic Quentin Letts reported that fellow actor Noel White said: “Ladies and gentlemen, this is not part of the play. Is there a doctor in the house?”

A doctor who was at Monday night’s performance in Guildford, Surrey, attended to the former Z-Cars actor on stage in front of the audience, including his daughter Rosalind.

Blessed – whose career in television, film and stage has spanned six decades – returned 20 minutes later after being clapped off by the audience, Letts reported.

In his review, Letts added: “After being given a cup of sweetened tea, he returned to the stage after 20 minutes to apologise to the final-preview audience for the interruption.”

Blessed reportedly said: “I feel such an idiot and am not in the habit of doing this, but I have little fibrillation.”

At the curtain call, as some other cast members were said to be in tears, Blessed patted his heart and gave a thumbs-up gesture, Letts said.

Blessed’s agent, Stephen Gittins, said in a statement: “Brian would like to thank everyone for their concern. The press night was an amazing success. Brian is thrilled to be working with the Guildford Shakespeare Company and is looking forward to the rest of the run at Holy Trinity Guildford.”

More theatre coverage

Brian Blessed pictures quiz: identify the mighty actor’s roles

This week’s theatre: King Lear | Fleabag | The Hard Problem

Kevin Elyot’s My Night With Reg: ‘the perfect West End play’

Wallace Shawn: ‘I live off doing animal voices in cartoons’

Truth, Lies, Diana review – tawdry drama commits crimes against theatre

Cathy Tyson: ‘Bob Hoskins helped me be unafraid as an actress’

Faith Healer review – Brian Friel’s hero gets a Bryan Ferry makeover