Boris Johnson has attacked the Mayor of London, accusing him of "squandering" money.
Addressing the Commons in his first-ever Prime Minister's Questions, Mr Johnson said it was time to "get rid of Sadiq Khan".
His comments came after a query from Labour MP Karen Buck, over his pledge to get thousands more police officers on the streets after they “plummeted” while he was Mayor.
Mr Johnson said it was “absolutely bizarre” that a Labour MP would “ignore the role” of Sadiq Khan in dwindling police figures.
“I left him £600 million by the way, and Sadiq Khan squandered it on press officers. The faster we get rid of Sadiq Khan and get more police officers out on the street the better,” he said.
“That is, in my view, the best possible argument for [Conservative candidate] Shaun Bailey as Mayor of London.”
In response, Mr Khan accused the Prime Minister of being "petty".
He tweeted: “Petty and inaccurate point-scoring does absolutely nothing to help our overstretched police tackle violent crime across the UK.”
PMQs began with a rapid back-and-forth between the Prime Minister and Jeremy Corbyn, as the Labour leader demanded Mr Johnson reveal signs of progress on a deal with the European Union.
“I asked what proposals have been put to the European Union, we asked yesterday, many colleagues asked, and the Prime Minister seems utterly incapable of answering. Any rational human being would assume therefore none have been put and there is no answer,” he said.
The Prime Minister responded: “You don’t negotiate in public and we are making substantial progress and we will get that backstop out.”
He repeatedly referred to the opposition attempt to prevent a no-deal Brexit as a “surrender Bill” that would wreck any chance of further negotiations.
Mr Corbyn said the Prime Minister had been in power six weeks and had done nothing to change Theresa May’s Withdrawal Agreement “which he twice voted against”.
The Labour leader continued: “I really fail to see how I can be accused of undermining negotiations, because no negotiations are taking place."