Billy Connolly has vowed to stay out of political discussions following a backlash to his opinions on Scottish independence.

The 69-year-old Scottish actor and comedian said: “Whenever I open my mouth I get it slapped shut. I’m told to mind my own business, to learn what I’m talking about.

“But I’ll tell you what, I don’t like showbusiness people lecturing the public on how they should vote anyway. I’ve always found that a kind of precocious state, and I’ve done it before you know, and when I look back at some of the things I’ve said I feel kind of stupid.”

Connolly has been vocal in his disapproval of Scottish independence in the past, but admitted that 2012 has been “a very interesting time for Scotland”.

He said: “I would like to know with these things, these master moves, how much it’s going to cost the people to do this, do they need another layer of government, and how it’s going to affect the average person, the average Joe. Is it going to affect his life? If it’s for the better, it’s up to him.

“But Scots are very capable of making up their mind without my tuppence worth.”

The actor was speaking as he was joined on the red carpet by co-stars Sir Tom Courtenay, 75 and Sheridan Smith, 31 to promote his latest film Quartet.

The British comedy, directed by Academy Award winning actor Dustin Hoffman, follows four elderly opera singers who are reunited in a specialist retirement home.

Hoffman recruited veteran actors Dame Maggie Smith and Pauline Collins to complete the star-studded cast.

Speaking about Dame Maggie, Connolly revealed that the 77-year-old Downton Abbey star has a secret talent.

“She does a brilliant Glasgow accent. She had an aunt in Glasgow and she used to go and spend summer times there, so we had a good laugh,” he said.

Quartet will be released in cinemas from January 1 2013.