Firth criticises 'plastic' actors

Firth is currently starring in Dorian Gray

Colin Firth says it is "a disaster" for actors to have Botox injections and plastic surgery.

The Mamma Mia! star said it was "catastrophic" to undergo facial cosmetic surgery if you wanted to be able to express yourself as an actor.

"Your face is supposed to move if you're going to act," the 48-year-old told BBC Radio 5 live.

"Why on earth would you take a violin and make the strings so that they don't vibrate?" he added.

"Injecting something in to your face so it's paralysed, or cutting bits of it up so that you take any signs of life out of it is catastrophic if you're going to express yourself in any way at all."

Botox injections, which have become increasingly popular in Hollywood, temporarily paralyse muscles in the face, making it virtually impossible to frown or raise your eyebrows.

But Firth said he was not totally against people having cosmetic surgery if they could "afford it and don't mind the pain".

He admitted he would "do it tomorrow if I thought it would look good - but I haven't seen anything I think really works that well".

The star is currently promoting his latest film, Dorian Gray - an adaptation of Oscar Wilde's novel about a man who stays eternally youthful.

He stars as Lord Henry Wotton, who tempts the title character, played by Prince Caspian actor Ben Barnes, into a life of hedonism.