Senior policing and political figures, including the prime minister, have defended police chief Sir Ian Blair amid growing calls for his resignation.
Sir Ian Blair had not misled the public, said the MPA chairman
The criticism follows an anti-terrorist police raid in Forest Gate, London.
Metropolitan Police Authority chairman Len Duvall said questions over the raid remained but insisted it had not undermined his confidence in Sir Ian.
Ken Livingstone backed the police but said claims of interference from security services should be answered.
Tony Blair's spokesman said: "The prime minister continues to give his full support to Ian Blair - full stop."
Several newspapers called on Sir Ian to resign over the weekend.
Damian Hockney, member of the Metropolitan Police Authority, which scrutinises the London force, said the MPA was split on the issue.
He told BBC Radio Four: "I think Sir Ian is now the wrong person, we need courageous and strong leadership at the moment, and he might have been the person to provide it some time ago, but not now."
Hundreds of people took part in a protest outside Scotland Yard on Sunday, calling the arrests "unbelievable".
The house in Forest Gate was raided by more than 250 police
The president of the Association of Chief Police Officers President, Ken Jones, said: "It is right and proper that the tragic events of those dark days be fully scrutinised.
"But it is not right and proper that superficial armchair judgements are now being arrived at based on leaks, gossip and innuendo.
"It seems that Sir Ian Blair has somehow become a lightning rod for the collective profound shock and anger over what happened last year, this is manifestly unfair."
The solicitor for the two brothers arrested during the raid told the Observer they planned to sue the force.
Mohammed Abdulkahar, 23, and Abul Koyair, 20, were held for a week on suspicion of terrorism involvement but released on Friday without charge.
Mr Abdulkahar was shot and injured during the raid, which police said followed "specific intelligence" of a terrorist threat.
Mr Duvall, who has asked for a police report into the raid, said questions needed to be asked about the quality of the intelligence behind it and why 250 police were involved.
But he said he did not believe Sir Ian had misled the public.
He said: "At this moment in time, Sir Ian Blair and his management team enjoy the confidence of a substantial majority of the police authority and the government and the mayor of London."
Chairman of the Home Affairs Select Committee John Denham told the BBC he too still had confidence in the Met chief.
"If he is held personally responsible for the shooting in Forest Gate through some failure or activity, or if he's held personally responsible for the shooting [last July of Jean Charles de Menezes] then clearly he's in serious difficulty - but aside from those two risks I think he's actually doing a good job leading the Met and should stay."
A senior security source told the BBC MI5 and the police had stood "shoulder to shoulder" over the decision to raid the house in east London.
This followed claims police had doubts about the intelligence but were told to go ahead with the raid after it was referred to the government's security and intelligence co-ordinator, Sir Richard Mottram, said BBC home affairs correspondent Danny Shaw.
London's mayor would be seeking assurances the police had not been bullied into carrying out the raid, he said.
Mr Livingstone told BBC Radio 4's Today programme he had not been briefed on the claims of political interference, but had read of them and found them "very worrying indeed".
"I think Londoners are prepared to accept that the Commissioner of Police has the right to initiate these sorts of raids, has the power and responsibility.
"We have always worked on the basis that they are free from political interference. I can't tell Sir Ian Blair what to do. He has complete operational freedom," the mayor said.
He added he had confidence in Sir Ian and dismissed complaints over his decision to deploy 250 officers for the 2 June raid.
In a separate development the News of the World has said Sir Ian would be criticised by the official inquiry into the shooting of Brazilian Jean Charles de Menezes in July.
Both the Home Office and the Metropolitan Police have refused to comment on the claims.