Sir Ian Blair has been backed by the home secretary
Members of the London Assembly have passed a vote of no confidence in Sir Ian Blair, the Met Police Commissioner.
Conservatives and Liberal Democrats on the assembly united to ensure the motion was passed by 15 votes to eight.
Addressing members before the vote, Sir Ian repeated his apology for the fatal shooting of Jean Charles de Menezes in 2005 but insisted he would not resign.
He said his force would not appeal against the conviction for breaching health and safety laws.
In 2005, Mr de Menezes was shot dead by firearms officers on the London Underground after he was mistaken for a suicide bomber.
The motion, which called on the Metropolitan Police Authority to sack Sir Ian, was passed after the commissioner was questioned for two hours.
However, the assembly has no powers over policing and it cannot compel Sir Ian to stand down.
Conservative group leader Richard Barnes said the decision of the Old Bailey jury to convict the Met over Mr de Menezes' killing had highlighted "corporate failures on a gigantic scale" within the force.
He added: "An innocent man died. Someone has to be held responsible, someone has to be held accountable."
Sir Ian told the assembly that he would have resigned if he had been guilty of "a series of failings" .
However, he said it would be wrong for him to stand down on the basis of one operation going wrong when the Met had successfully countered a string of terrorist threats.
He added: "There are three options here. There is resign now and walk away. There is cling on, and be pushed out.
"Or there is the one that I am going to do, which is survive.
"Every time I have spoken about this I have apologised for that death.
"We've now had enough time to consider clearly what we should do about the verdict and we will not be appealing it."
He acknowledged that he had made "widely-publicised" mistakes, but said that Londoners would judge him on falling crime figures and safer streets.
Eight Conservative members of the Assembly, five Liberal Democrats, one Green and the One London member, Damian Hockney, voted for the motion, which expressed "lack of confidence in the Commissioner's stewardship" and urged him to resign.
Sir Ian was supported by seven Labour members and one Green.
London mayor Ken Livingstone, who has given Sir Ian his backing, said that a "cynical campaign" was being waged against the commissioner.
He said: "Today's vote by the London Assembly on the Met Commissioner shows why the government was right to give the London Assembly no powers whatever in policing."
"Al-Qaeda must be laughing at us while we busy ourselves pillorying the police who keep us safe."
Jacqui Smith has come out in defence of Sir Ian Blair
The chairwoman of the Police Federation of England and Wales, Jan Berry, said the force had been convicted - not the commissioner - and as such she had deliberately not commented on his personal circumstances.
"What we have witnessed since is more about political opportunism than it is about seeking improvements to policing.
"Using the Metropolitan Commissioner as a political football is a cheap shot that does absolutely nothing to instil public confidence and trust in politicians or the police service itself."
Ken Jones, President of the Association of Chief Police Officers, condemned what he called the "unwise" vote.
"We note that the assembly divided largely along political lines," it said.
"Policing and politics make for a volatile mix. The prism of party interests is a flawed perspective from which to judge those who are called upon to make life or death judgments."
The Independent Police Complaints Commission (IPCC) is due to publish its report into the incident on Thursday.
The commissioner may also learn shortly whether he is to face another vote of confidence at an emergency meeting of his force's police authority.
Home Secretary Jacqui Smith has written to her Tory shadow, David Davis, criticising his call for Sir Ian's resignation.
Ms Smith told reporters that politicians like herself and Mr Davis should rally round the police.
She said she retained "full confidence" in Sir Ian and the Met.
Later in the Commons, she told MPs: "Opposition politicians in this house and the [London Assembly] who have called for the sacking of the commissioner will never have to face the split-second decisions in life and death policing operations that they do.
"But we should consider soberly and seriously the impact that our statements have on those who do have to do that; and I believe responsible politicians should be backing those who are protecting us against the terrorist threat."