Keith Vaz, the Labour MP for Leicester East, told the Commons ministers must stop the game, Bully, going on sale in the UK to prevent a surge in attacks on pupils.
Child welfare campaigners have also urged the Government to ban the game, not yet approved by the British Board of Film Classification (BBFC). "If they don't make any changes will the Government use its powers to ban this video?" Mr Vaz asked Geoff Hoon, the Leader of the House, standing in for Tony Blair.
Mr Hoon said the Government worked to ensure young people had access only to games with appropriate content. He added: "The distributors have yet to put this particular game to the BBFC ... So the precise nature of its contents is not yet fully known."
Mr Vaz has been an opponent of violent games since the hammer murder of Stefan Pakeerah, 14, in Leicester last year. His parents said his killer, Warren Leblanc, had been obsessed by the game Manhunt, published by Rockstar North, which also produced Bully.
Sue Clark, a spokeswoman for the BBFC, said ministers had no power to ban video games. "We can ask for modifications but no subject is actually taboo. No government has put pressure on the BBFC since we were founded in 1913."
The BBFC has only once refused to certificate a game. In 1997 it rejected Carmageddon, in which players scored points by running over pedestrians. That was overruled by the Video Appeals Committee.