On the Graham Norton Show Friday night, Sir Billy Connolly is set to give viewers an update on his battle with Parkinson’s disease, saying he is losing the ability to write.

He expresses how much this “breaks [his] heart”, because he loved writing letters, Press Association reports.

The 78-year-old comedian, also known as The Big Yin, was diagnosed with Parkinson’s disease in 2013 and retired from live performances five years later.

Connolly has continued to record programmes and make TV appearances, as he joins Graham Norton via video-link from his home in Florida.

He spoke about his autobiography, ‘Windswept and Interesting’, saying: “The rules of being ‘windswept and interesting’ are doing as you please and not taking lessons from anyone.”

He gave an update on his illness, saying he has good and bad days.

“It’s creeping up on me and it never let’s go. I walk like a drunk man and have to have help. So, life is different, but it is good,” he said.

He continued: “I have lost the ability to write, and it breaks my heart as I used to love writing letters to people.

“My writing went down the Swanee and is totally illegible, so I had to find a way to record everything, but then the recorder didn’t understand my accent so it kept collapsing and my family would have to sort it – it was a club effort!”

Other guests on the show include Jodie Whittaker, Tom Daley, Dame Eileen Atkins and Sir Lenny Henry. Coldplay will be performing.

The Graham Norton Show airs on BBC One at 10.35pm on Friday and is also available on BBC iPlayer.