Conservative attempts to introduce a new bill designed to strengthen protection for householders who tackle intruders were damaged after three of the party's MPs failed to turn up for a crucial committee hearing.

The absence of Chris Grayling, Andrew Mitchell and Hugo Swire means the Householder Protection Bill will have no time to become law before parliament is dissolved for the expected general election on May 5.

Michael Howard had personally led a high-profile launch of the Bill, using it to challenge Tony Blair to prove he was tough on crime.

Charles Clarke, the home secretary, immediately attacked the Tories.

In a letter to David Davis, the shadow home secretary, Clarke said: "It is now absolutely clear that you are not concerned about this issue at all.

"Your party is just trying to prey on people's worries as a cynical election ploy without having any real commitment to doing anything about it."