Boris Johnson has pledged to boost police numbers by 20,000 in three years if he wins the leadership contest.
Police officer numbers in England and Wales have dropped by more than 20,000 since 2009, from 144,353 to 122,395.
Mr Johnson said the £1.1 billion proposal would be funded by “headroom” reserves set aside by Chancellor Philip Hammond.
“We are going to use some of the existing headroom, quite a small amount, about £1.1 billion, to put more police officers out on the street and I think that is what the public want,” he said.
“We are still well within the £26 billion that the Chancellor squirrelled away quite prudently, the money is going on education, a little bit on broadband - and that is already allocated - and on policing as well.”
Mr Hammond has publicly warned Mr Johnson and rival Jeremy Hunt that in the event of a no-deal Brexit this money would be used to deal with the aftermath of the withdrawal, and cannot be spent elsewhere.
Meanwhile, Mr Hunt said he would move to legalise fox hunting if he became Prime Minister.
He said fox hunting was “not particularly my thing” but was “part of the countryside”.
“I think we have to recognise that in terms of the balance of the countryside it's part of our heritage,” he said.
Labour party chairman Ian Lavery has slammed the proposal, saying fox hunting was a “barbaric practice”.
“We've had Johnson's tax cuts for the wealthy, a race to the bottom on no-deal Brexit, and now a pledge to bring back this barbaric practice that Labour had proudly banned,” he said.