Washington, Sept 10 British actor Colin Firth has condemned actors who go under the knife to remain youthful.

'Bridget Jones Dairy' star insists it is "catastrophic" for big screen stars to undergo cosmetic procedures.

He said that the actors should not try to halt the ageing process - because stars can't express themselves on-screen if they have their faces tampered with.

"Your face is supposed to move if you're going to act. Why on earth would you take a violin and make the strings so that they don't vibrate?" Contactmusic quoted him as saying.

"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," he added. (ANI)