Yow keep going, Billy, says funnyman Tommy Mundon

But Tommy, now aged 79, who quit the Black Country circuit last year because of his ill-health, had this piece of advice for the Big Yin – 'keep going as long as yow can'.

Billy, aged 70, revealed this week that he has undergone surgery for prostate cancer and is being treated for the early symptoms of Parkinson's.

Tommy, who lives in Alexandra Road, Halesowen, was diagnosed with Parkinson's two years ago and, at first, carried on performing.

But the condition increasingly made it harder to remember his lines and he finally threw in the towel in June last year.

Billy admitted earlier this year that he had started to forget his lines during performances and he has just been diagnosed with Parkinson's after undergoing surgery in America for prostate cancer.

He has, however, vowed to continue his stage and screen career, and a spokesman for him said: "Billy has been assured by experts that the findings will in no way inhibit or affect his ability to work, and he will start filming a TV series in the near future, as well as undertaking an extensive theatrical tour of New Zealand in the new year."

Tommy, who was a stalwart of the Black Country Night Out variety shows, said of living with Parkinson's: "Sometimes I'm up, sometimes I'm down – and sometimes I'm very down. It's a complicated disease.

"I'm a fan of Billy Connolly and it was a blow to hear he now has it – it just shows it can happen to anybody at any time.

"I was lucky mine was diagnosed early – and hopefully Billy will be able to get the best treatment and keep going and making people laugh. I know earlier this year Billy said he was beginning to lose the plot – and I know what that's like."

The Black Country comedian, who counts Liverpool funnyman Ken Dodd among his admirers, found out he had the condition after he fell at home while dashing to answer a phone call and banged his shoulder.

"My doctor saw me walk up and down a couple of times – and said, 'Tom, I'm afraid you've got Parkinson's'.

"Ever such a lot of people have got it – I know five or six down our road that have it."

Although there is no cure for Parkinson's, symptoms, including memory loss, can be controlled using a combination of drugs and therapies.

Billy and Tommy are among 127,000 people in the UK currently living with Parkinson's. Last year, actor Bob Hoskins disclosed he had been diagnosed with it at the age of 69 and announced his immediate retirement.

But US actor Michael J Fox, who was diagnosed with the disease in 1991, is still working and now plays a TV reporter who returns to the screen five years after developing Parkinson's.

"I've had brilliant treatment from the team of nurses at Russells Hall Hospital," said Tommy, who now goes once a week to the day centre at Stourbridge's Mary Stevens Hospice to give his wife, Val, a break from caring for him. "I'm doing all right but missing showbusiness.

"Lots of folk stop me and say how sorry they are I'm not on stage any more – and that's lovely of them, but it's like a knife going in the back when I think I can no longer do it."