Violence is comic book says Firth
Colin Firth said he agreed the certificate for his new film Kingsman: The Secret Service should not be lower than 15, but insisted the violence was "comic book".
The Oscar-winning actor plays spy Harry Hart in the action movie, directed by Kick-Ass' Matthew Vaughn and based on the comic book The Secret Service created by Dave Gibbons and Mark Millar.
The film, co-written by Vaughn and Jane Goldman, also stars Sir Michael Caine as head of the Kingsman spy agency, Chester King, and Samuel L Jackson as villain Richmond Valentine, an internet billionaire who is trying to take over the world.
Firth joined co-stars Mark Strong, Taron Egerton, Sofia Boutella and Sophie Cookson on the red carpet in London's Leicester Square, along with Take That, who performed their new song Get Ready For It, which features on the soundtrack.
Firth, 54, insisted the film, which contains some scenes of graphic violence, should be allowed to find humour in it.
He said: "It's a very complicated question in a way, because unless you believe there should never be any physical conflict in any storytelling, then it has to become a conversation about how it's done and what it's for. And if you've ever seen Laurel and Hardy or a Punch and Judy show, or a pantomime, or Monty Python, then of course fights are there to be funny.
"I think, of course it's intense and extreme, I wouldn't think the certificate would belong any lower than 15, so I think you have to see the film and decide for yourself where your threshold lies.
"For me, it's comic book, it's playful, it's satirical, and it's not gory. I think you're going to see an awful lot worse by switching on the TV - blood and brutality - than you see in his film."
Director Vaughn denied any scenes were cut to lower the certificate from 18 to 15, and added: "It's always been 15 and hopefully it will remain 15.
"Ever watched a thing called Tom and Jerry? Did it make you laugh as a kid? There you go.
"We all have violence in us, it's part of human nature. But I want to do it in a way that's entertaining and fun and not serious and gratuitous. We're a comic book film."
Testament of Youth star Egerton plays Kingsman recruit Eggsy, who becomes Harry's protege.
The 25-year-old said of the violence: "I don't think it's intended to find it funny. I think it lends something to the world we're creating. We're demonstrating the extremity and the prowess these secret agents have.
"I think if you're laughing at it, you might have a bit of a screw loose."
Algerian actress and dancer Boutella, 32, stars as Valentine's henchman, an assassin called Gazelle who uses her sharpened prosthetic legs as lethal weapons, while Strong plays Kingsman mentor and gadget guy Merlin.
Strong admitted violence was a "delicate subject".
He said: "Maybe it should be funny, maybe that's the point. If you make it funny it doesn't terrify people."
Kingsman: The Secret Service opens in cinemas on Thursday January 29 2015, certificate 15.