Natalie Portman arrives at the premiere of V For Vendetta

V For Vendetta stars Natalie Portman and is set in 2050 with Britain portrayed as a fascist society.

The Star Wars actress plays a woman who is involved in the attack, while Hugo Weaving's character tries to free the country from its restrictive regime.

Portman had to shave her head on-camera for the role, and admitted: "I only got one shot to do it so it was difficult."

July bombings

Irish actor Stephen Rea, whose character leads the fight against the plot, denied the film glorifies terrorism.

This is despite its similarities to Guy Fawkes' famous attempt to destroy the Westminster parliament in 1605.

"It's about the erosion of human rights," he said, "about governments controlling beyond the point that's necessary or appropriate, about giving powers to themselves that they don't need."

Portman has shaved her head before: this was in 2005

Filming took place before last July's terrorist attacks on London but producer Joel Silver felt there was no need to change any part of the script as a result.

"It didn't affect the film on the cutting room floor," he said, adding: "it's a good time to tell this story."