Video report by ITV News Reporter Rachel Younger
The party leaders clashed on Brexit, the NHS and trust among other issues, with neither seemingly landing a knockout blow.
Liberal Democrat leader Jo Swinson, SNP leader Nicola Sturgeon, Brexit Party leader Nigel Farage and Green Party leader Sian Berry are each setting out their own electoral offer and giving their reactions to the head-to-head debate.
Ms Swinson insisted stopping Brexit would be a simple process and repeated her promise she would revoke Article 50 if the Lib Dems are voted into power.
She said it would be a “simple letter” written to the European Union to cancel Brexit.
On Mr Johnson's and Mr Corbyn's performance in the debate, she said: “You’ve got two men squabbling over how to do Brexit and [are] not really focused on the future at all.”
She also repeated her pledge not to work alongside either of the two leaders, telling ITV News' Nina Hossain: “Liberal Democrat votes are not going to put either Boris Johnson or Jeremy Corbyn into power because I believe our country deserves better than either of them.”
Asked if she would keep her word even if that forced another General Election, she admitted "Brenda from Bristol probably wouldn't be too chuffed".
She added: “I genuinely believe that what’s on offer from both of those men is not good enough for our country and I don’t think that we should feel somehow that we have to accept it.
“Even if they change their leader I don’t think there is any guarantee that they would be a more moderate figure.”
Asked if she would be prepared to use a nuclear weapon, she answered simply "yes" during a quickfire question-and-answer session.
After Mr Johnson claimed a deal between SNP and Labour has already been done to support each other – which Mr Corbyn denied strongly – Ms Sturgeon said “no deal has been done”.
She made clear she would not support Boris Johnson or “any Tory” but admitted she would look at issues the SNP wants to pursue if Labour are in a position to form a minority Government.
“Crucial for me of course would be an acceptance that Scotland’s future was up to the people of Scotland to decide and that Westminster didn’t have a veto over that,” she said.
“I believe an independent Scotland could be a much fairer, more equal, more prosperous country.
“And of course we could sit at the top table in the European Union wielding the kind of influence that we’ve all watched Ireland wield over the last three years.”
Ms Sturgeon did rule out a coalition but said she was open to a "more informal arrangement" - with a Scottish independence referendum next year.
When asked during quickfire questioning about a hard border between Scotland and England, she said that is not her policy or objective.
She insisted Brexit threatens borders, not the SNP's position.
Mr Farage insisted his decision to stand down candidates had nothing to do with Donald Trump and said he attempted to form a Leave alliance to “romp the election”.
He added the Tories have put Brexit at risk by refusing to make concessions and by refusing to stand aside for the Brexit Party in seats they have never won.
“No I didn’t do it for that reason, absolutely not,” Mr Farage insisted on the question of Trump’s influence.
“It’s no secret Donald Trump is a Brexiteer, he is a friend of mine. He’s been saying for months he thought Boris Johnson and I should work together.
“And actually I’ve been trying to put together a Leave alliance to say to the Conservatives and others this issue is bigger than any political party.
“I think if we had, we’d have got senior Labour figures on board.”
He argued he has not put Brexit at risk by challenging the Tories. Instead, he claims the Conservatives would be responsible for not delivering Brexit.
“There’s only one party that’s put Brexit at risk, a party that says it believes in Brexit, that’s put it at risk, that’s the Conservative party by refusing to make any concessions at all.
“There are around a 140 seats in this country that the Conservatives have never won and will never win.
“If the Conservatives cared about us becoming independent, free of the EU, if it really mattered to them they would have actually stood aside and let us be the challenger.”
He also made the case for more “direct democracy”.
“If people want referendums, they should have the right to call them,” he said.
He also argued the country should have a written constitution that says any referendum is legally binding.
Ms Berry said it was “outrageous” that Mr Johnson and Mr Corbyn didn’t bring up the climate emergency alongside Brexit during the debate.
She outlined her belief that spending £100 billion per year over the next decade would help the country become carbon-neutral by 2030 – a target she believes both the Labour and Tories should stick to as well.
“I can’t believe that neither of those two leaders brought up the most important issue that we face alongside Brexit,” she said.
“I think it’s outrageous, everyone must have been at home crying out for Caroline Lucas, for me, for [Green Party co-leader] Jonathan Bartley to be there to hold them to account.
“The young people that are out on the streets literally begging us to do something about this must have been feeling so let down.”
Asked how realistic it is to turn the UK into a carbon-neutral country, she insisted scientists have dictated that as the deadline.
“The scientists are very clear that we have to become carbon neutral if we are not going to face a 50/50 chance of runaway climate chaos,” she said.
“These are not targets we take lightly.”
She argued it is important to take action “at all levels”, saying Labour cannot go back on the 2030 target and the Tories cannot hang on to a 2050 target.
During quickfire questioning, she was asked if it could be justified for climate protesters to stop people going to work on public transport.
She said Extinction Rebellion do a fantastic job but admitted she does not agree with all of their tactics.
Catch up on the ITV debate