A former senior Metropolitan Police officer has said he is considering running for mayor of London.
Brian Paddick took early retirement from the force in May
Ex-deputy Assistant Commissioner Brian Paddick, who retired from the force in May, said he is thinking about standing for the Liberal Democrats.
He also criticised the current mayor, Ken Livingstone, saying he should be a "critical friend" of police rather give them "unequivocal support".
Mr Livingstone said he was willing to criticise police if they were wrong.
Mr Paddick took early retirement from the force after clashing with Commissioner Sir Ian Blair over the shooting of Jean Charles de Menezes in July, 2005.
The openly gay former officer said that he was surprised by Mr Livingstone's "complete support" for police even after the Brazilian's death in Stockwell, south London.
"I am a little bit concerned that the mayor, rather than being an unequivocal supporter of the commissioner and the Metropolitan Police, should actually be a critical friend.
"Londoners are not 100% satisfied with the Met and I think, as the people's representative, the mayor should say: 'Look, you need to raise your game'."
Reacting to Mr Paddick's criticism Mr Livingstone said: "I don't think anyone will take seriously the idea that I am unwilling to criticise the police, or any other institution for that matter, when they are in the wrong."
Mr Paddick said the prospect of taking on Mr Livingstone and Boris Johnson, who could be the Tory mayoral candidate, was tempting.
"They are both formidable in their very different ways and it is a very big decision to take on these giants in that sort of competition," he said.
"Nominations don't open until September and I am still thinking about whether I should go for that or not."