Sir John Stevens has welcomed Tony Blair's pledge to consider changing the law to clarify how much force people may use to protect their homes.
The current law allows 'reasonable' force to be used in defence
The Metropolitan police commissioner said at the weekend that laws need to protect householders who use force to defend their homes against criminals.
On Wednesday, the Prime Minister said he would support a law change, if consultations showed it was necessary.
He pledged to consult on the issue with police, prosecutors and law officers.
Sir John, who is stepping down as commissioner on January 31, was speaking at the launch of The Official History of the Metropolitan Police, at a reception also attended by Home Secretary David Blunkett.
He said the law needed changing, as it currently revolved around
a common law principle and should be put into statute, and also needed
"People in their houses need to know they can defend themselves," said Sir John.
"Since the Tony Martin case, people have had difficulty in knowing what
they can do. Victims have said they didn't know how far they can go.
"I haven't come out with this comment off the top of my head. It is as a
result of listening to what people say, talking to victims. Therefore I know as
an absolute certainty the law needs to be clarified."
Tony Blair has said he thought a change could be needed to send a "clear signal" the government was on the side of the "victim not the offender".
But Tory leader Michael Howard accused Mr Blair of jumping on his party's "bandwagon" over the issue.
Currently householders are allowed to use "reasonable force" to defend themselves and their property against intruders.
But the Tories have unveiled plans to change the law with a private members' bill so householders would not face prosecution unless they used "grossly disproportionate" force in self defence.
Mr Blair told MPs: "In the light of recent concern, it is worth looking at whether we don't have to clarify the law so that we send a very, very clear signal to people that we are on the side of the victim not the offender."
But he added that even though the number of cases in which a person would be convicted after taking on a burglar in their own home was very small he would consult and bring forward proposals to tackle the issue.