London suicide bomber Mohammed Sidique Khan's claim that UK foreign policy is "oppressing" Muslims was "rubbish", Prime Minister Tony Blair has said.
Khan's video message aired after the London bombings
Mr Blair, citing Khan's video message broadcast after the July bombings, said any "sense of grievance" about UK policy in Iraq was not justified.
Such views must be "challenged at every level", he told a committee of MPs.
In his video, Khan criticised British foreign policy, saying he was a soldier fighting a war on behalf of Muslims.
Giving evidence to the influential Commons liaison committee, Mr Blair said: "We have got to challenge this sense of grievance because there is no justified sense of grievance.
"When I saw the video of one of the suicide bombers from 7 July talking about what had happened I looked at it and said 'this is someone brought up in this country, who has all the freedoms that they have in this country, who has got a good standard of life as a result of being in this country'.
"One of the things we have got to do is challenge the notion that he can stand up and say 'this is a country that is oppressing people of my religion'. It's rubbish."
During the two and a half hour session before MPs, which covered a range of subjects, Mr Blair denied it took a terrorist attack in London to make the government take seriously the need to build bridges with the Muslim community.
He said he did not agree with some aspects of the way the anti-terror message was being spread.
"There is a tendency for us to go into the community and say 'we kind of understand how you feel like you feel, but we disagree with your methods in dealing with it'.
"I don't agree that there is a sense of grievance. People may disagree with this or that aspect of foreign policy but it's not merely that nothing justifies the act of terrorism, the actual grievance about foreign policy is misplaced.
"Whether America is right or wrong, or Britain is right or wrong in its foreign policy, it is not pursuing it because of the religion of the people concerned."
Mr Blair said he had "absolutely no doubt" that extremists would use the excuse of Western foreign policy on Iraq, Afghanistan, Palestine or Chechnya as a justification for their terrorist activities.
But he insisted that the effect of Britain's foreign policy in Iraq and Afghanistan was in fact to allow millions of people the right to vote.
He told MPs: "The idea that you can possibly justify killing innocent people on the London Underground or London buses by reference to what is happening in Iraq or Palestine is absurd."
Mr Blair also told MPs international agreements are outdated in the face of the current terror threat.
The government faces legal challenges over plans to deport foreign terror suspects, provided their home country gives undertakings about their treatment.
Critics argue the policy will break refugee and human rights conventions enshrined in international law. Mr Blair said: "This was all done arising out of the Second World War and the Holocaust and so on for perfectly understandable and absolutely right reasons.
"But it doesn't very much correspond with the reality that most of us are facing today and I think that reality is very, very tough."
He insisted he was not being "casual about civil liberties".
He also defended Britain's record on promoting equality between ethnic communities, saying it was "at least as good" as any other country in Europe.