The PM has been dogged by the fact that it was on her watch as Home Secretary that police numbers were slashed by 20,000.
Mrs May was forced to defend her record on police cuts amid increasing pressure over a 20,000 drop in the number of officers on the streets between 2010 and 2016.
In the wake of Saturday's terrorist attack in London, the third major terror incident to hit the United Kingdom in as many months, May's record as Home Secretary has been called into question.
In an interview with ITV News, Corbyn said May should resign because she presided over government cuts which reduced police numbers by 20,000 when she was home secretary, following the third deadly terror attack the United Kingdom has faced in three months.
Mr Clegg said there was a "stark difference" in the approaches of the Tories and Lib Dems after the 2015 election, with spending plans for the future also "significantly different".
Corbyn said: "As Labour set out in our manifesto, we will recruit another 10,000 new police officers including more armed police who need to be properly rewarded as well as 1,000 more security services staff to support our communities and help keep us safe".
In a question and answer session on the campaign trail on Monday, Mrs May repeatedly refused to say she was wrong to cut police numbers while she was in the Home Office.More news: Novak Djokovic, Rafael Nadal Speak on Safety at Wimbledon After London Attack
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"The Commissioner of the Metropolitan Police has said that the Met is well-resourced, and they are, and that they have very powerful counter-terrorism capabilities, and they do, we have protected counter-terrorism policing budgets", she told a press conference.
'Let's be very clear.
After a suicide bomber killed 22 people in Manchester on May 22, British police and politicians were furious when United States media, citing intelligence sources, named the perpetrator and published photos of evidence from the scene.
Asked about Hilton's comments, May said: "I don't think I'm the only person in Westminster who has found himself on the receiving end of a few comments from Steve Hilton".
It seems it's not just Theresa May who is for turning... "We have seen a protection or an increase in the budget for counter-terrorism policing", she said.
He said: "But their job is made much harder when cuts are made to their resources".
Tim Farron, the Liberal Democrats leader, said: "Theresa May must level with the British people and accept that on her watch armed officer numbers were cut".