The head of the Metropolitan Police, Sir Ian Blair, has resigned - the first commissioner to do so in more than 90 years.
Sir Ian Blair took over as Met commissioner in 2005
Sir Ian took on the job in 2005 and had been due to serve until 2010.
He said he was stepping down "in the best interests of the people of London and the Metropolitan Police Service".
A variety of public figures have been giving their reaction to his departure.
GORDON BROWN, PRIME MINISTER
"Ian Blair has made a huge personal contribution to the safety and security of our country, leading the national police effort against terrorism and the fight against crime, successfully introducing neighbourhood policing in London and cutting crime in the capital very significantly.
"I congratulate him and his officers, and of course I want to pay particular tribute to Ian's leadership when London experienced the most serious terrorist attacks ever on British soil."
BORIS JOHNSON, MAYOR OF LONDON
"Sir Ian Blair has made a lasting and distinguished contribution to policing in London and across the UK for the last 34 years.
"But there comes a time in any organisation when it becomes clear it would benefit from new leadership and new clarity of purpose. I believe that time is now.
"I have the highest respect for Sir Ian and I'd like to make it absolutely clear that there was no particular story, or no particular allegation, that was uppermost in our considerations.
"But he and I agreed that this was an opportunity, with my taking the chair of the MPA, as I am next week, an opportunity for a clean break and a new start for policing in London and I think that is the right thing to do."
ERIONALDO DA SILVA, DE MENEZES FAMILY SPOKESMAN
The spokesman for the family of Jean Charles de Menezes, who was shot dead by police officers in mistake for a suicide bomber in 2005, said: "Ian Blair should have resigned three years ago when he and his team killed the wrong man.
"We don't want his resignation to deflect attention from the inquest, because that's the moment the family has been waiting for, the moment they are seeking the truth.
"His resignation doesn't change anything for us."
KEN LIVINGSTONE, FORMER MAYOR OF LONDON
"What this does is makes the whole role of the commissioner much more political.
"Whoever is now appointed to replace Sir Ian Blair will know that there's a precedent that an incoming mayor feels they've got the right to change the commissioner of police.
"Boris basically ran against the commissioner in his election campaign. I think that is a very bad position to start with.
"I don't think it should be a political appointment. You want a good copper who can actually bring crime down not someone you feel politically is more closer to your viewpoint.
"I think this whole event has weakened the post of commissioner."
JACQUI SMITH, HOME SECRETARY
"Sir Ian has always had my support for the demanding and vital tasks that we expect of the Met.
"They go well beyond the effective policing of London - a tough enough job though that is - to the commissioner's national role in policing and tackling terrorism.
"I pay tribute to Sir Ian for the massive reductions in crime that his leadership of the Met has overseen and his continuing efforts to tackle gun, gang and knife crime.
"His part in leading neighbourhood policing across London has led to Londoners being safer and more confident.
"Sir Ian can be proud of his contribution locally and nationally."
DOMINIC GRIEVE, SHADOW HOME SECRETARY
"This is the right decision. We have been calling for Sir Ian to step down for almost a year - since the serial and systematic failings at the Metropolitan Police disclosed during the de Menezes trial - whilst Cabinet ministers from the PM onwards continued to express total confidence in him.
"It is now clear that they have shown a serious lack of judgement about the leadership of the most important police force in Britain.
"It is vital that a successor is appointed who can restore public confidence."
TONY MCNULTY, POLICING MINISTER
Responding to Conservative criticisms: "I'm afraid that shows the profound ignorance of Dominic Grieve when it comes to policing in London and the complexities of policing in London.
"For any shadow home secretary to speak in such bilious terms really, I think, shows him to be unfit for that shadow position.
"Any change in leadership is a chance for a fresh start, but if people think that all of a sudden controversy goes away from the Metropolitan Police then I think they have a sadly lacking view of the complexities and diversities of how to police this wonderful capital city of ours."
SHAMI CHAKRABARTI, LIBERTY
"Sir Ian held this position during incredibly testing times that would have tested any incumbent.
"We hope his successor and senior politicians will learn from the mistakes of the past.
"Both the public and the service need senior officers to be police chiefs not politicians. Political independence is vital to trust.
"We also hope that the Menezes family will feel that there has finally been accountability for their tragic loss."
CHRIS HUHNE, LIB DEM HOME AFFAIRS SPOKESMAN
"Sir Ian Blair had become part of the Met's problem, not its solution.
"His resignation is long overdue following a string of embarrassments for his force, including contracts given to friends, the shooting of Jean Charles de Menezes, accusations of racism causing chaos at senior levels and the politicisation of his role during the debates on detention for terrorist suspects.
"The Met now needs a tough professional, not a wannabe politician."
BRIAN PADDICK, FORMER DEPUTY ASSISTANT COMMISSIONER
"There is a lot to be dealt with, a lot to be cleared out, if you will, and I think it needs a new broom to deal with those issues, rather than anybody who might be seen to be tainted by what has gone on in the last few months.
"I don't think Londoners should be too concerned about a change at the top. I have said before, and I would maintain, that London will be better off with a new commissioner.
"I think some rank and file officers - those who felt that Ian Blair was a reformer, someone who was very pro-diversity - will be very disappointed to see him go.
"I think a lot of officers will see his position as untenable and will quite welcome the fact that there will be a new master at the helm."
LORD STEVENS, FORMER MET COMMISSIONER
"It is a sad day for the office of the commissioner of the Metropolitan Police Service."
DAVID BLUNKETT, FORMER HOME SECRETARY
"This is a sad conclusion to what's become a long-running and now successful attempt to dislodge Sir Ian Blair as Met commissioner.
"I believe that not only Londoners but, because of the key role of the Met in counter-terrorism, the country, will have lost an extremely able, experienced and successful professional.
"His drive and leadership in implementing the re-establishment of neighbourhood policing and the development of the local teams dedicated to serving the community has already made a profound difference to crime prevention and reduction."
SUPERINTENDENT DAL BABU, ASSOCIATION OF MUSLIM POLICE OFFICERS
"He has been a champion of diversity.
"Some progress has been made - there's still quite a lot to do within the police service - but he's nailed his colours on the mast in terms of diversity.
"He was an intellect - he was an incredibly bright individual. He's responsible for writing a number of articles in books and he developed safer neighbourhood teams."
LORD HARRIS, METROPOLITAN POLICE AUTHORITY
"The reality it that there has been a great deal of progress for the police in London under Sir Ian's commissionership and I wouldn't want us to lose sight of that in the face of some of the other issues.
"It's not really surprising that Sir Ian Blair felt that without the full support of the new administration of the police authority it would be difficult for him to carry on.
"In a way, that's what public accountability is all about."