- Video report by ITV News Political Correspondent Libby Wiener
Both Theresa May and Jeremy Corbyn have been forced to defend their records and answer tough questions from an audience as they faced a live television grilling.
The Prime Minister came under fire from members of the studio audience over her cuts to public services and her plans for social care.
While the Labour leader faced questioning on his attitude to security issues and past comments about the IRA and the Falklands War.
The pair each faced 20 minutes of questions from the audience with a further 18 minutes in front of interviewer Jeremy Paxman, with Mr Corbyn going first.
Appearing on a Sky News/Channel 4 "Battle for Number 10" broadcast, Mr Corbyn refused to be drawn on whether he would authorise a drone strike against a terrorist plotting overseas to attack the UK.
"It is a hypothetical question," he said.
"We have to look at the evidence that is there at the time to make that fatal decision one way or the other."
Mr Corbyn, a lifelong opponent of nuclear weapons who has made clear that he would never authorise their use, nevertheless indicated he would issue the customary final instructions to the commanders of the Trident submarine fleet if he became prime minister.
"I will write the appropriate letter to our commanders who are obviously very responsible, very loyal naval officers," he said.
Mrs May did not escape lightly either.
During her grilling from the studio audience, Mrs May was accused by a police officer of presiding over "devastating" cuts, asked by a midwife to justify her "chronic underfunding" of the NHS and heckled over school funding.
The 60-year-old insisted that she was determined to do the right thing for the country, referring to her reputation as a "bloody difficult woman".
She added: "Doing what is the right thing by the country. Sometimes you have to be difficult in order to do that."
Mrs May also reaffirmed that she would walk away from the forthcoming Brexit negotiations without a deal rather than accept a "bad" deal.
"I think you have to. In negotiations you have to recognise that you're not in there to get a deal at any price."
Many of the questions Mr Corbyn faced were based on his views on foreign policy and conflict.
One of the first questions to the 68-year-old came from an audience member who claimed the Labour leader had "openly supported the IRA in the past" by attending a commemoration for eight IRA members killed by the SAS in Loughgall in 1987.
Mr Corbyn said: "The contribution I made to that meeting was to call for a peace and dialogue process in Northern Ireland."
He was pressed by Mr Paxman over comments he made following the Argentine invasion of the Falklands that "young unemployed men" were being sent to the South Atlantic to die in pursuit of a "Tory plot".
The Labour leader said he did not believe it had been a "plot" but added: "Margaret Thatcher made a great deal of that issue at the time. I felt that she was exploiting the situation."
Mr Corbyn defended his description of the Palestinian group Hamas as "friends" and his comment that the killing of Osama bin Laden by US special forces had been a "tragedy".
"I think he should have been arrested and he should have been put on trial. And he could have been," he said.
Challenged by one man who said he liked the Labour manifesto but did not see Mr Corbyn as "someone who could run this country", the Labour leader said he saw himself as a listening politician.
"You should never be so high and mighty you can't listen to somebody else and learn something from them," he said.
While the majority of questions directed at Mrs May were based on her time as Home Secretary and austerity cuts.
During her session in front of the studio audience, Mrs May insisted she had given the police the resources they needed but acknowledged that numbers in England and Wales had fallen by around 20,000.
"What we had to do when we came into government in 2010 was to ensure that we were living within our means and that was very important because of the economic situation we had inherited," she said.
She was pressed by Mr Paxman over her climbdowns on a proposed Budget hike in national insurance and her social care changes just days after they were unveiled in the Tories' election manifesto - and what it would mean for the Brexit negotiations.
"What one's bound to say is that if I was sitting in Brussels and I was looking at you as the person I had to negotiate with, I'd think 'she's a blowhard who collapses at the first sign of gunfire'," he said.
She retorted: "I think, Jeremy, you will find that what the people in Brussels look at is the record I had of negotiating with them in Brussels and delivering for this country on a number of issues on justice and home affairs which people said we were never going to get, and I got those negotiations."