Jeremy Corbyn has dismissed Boris Johnson's pledge to "get Brexit done" by the end of January as "nonsense".

In the opening exchanges of the TV debate hosted by ITV, the Prime Minister warned the UK faced more "dither and delay" under a Labour government.

He said a vote for the Conservatives would be a vote to finally "get Brexit done".

"If you vote for us, we have a deal that is ready to go. Approved by every one of the 635 Conservatives candidates standing at this election," he said.

"As soon as we can get that deal through Parliament, as we can in the next few weeks, we can get on with the people's priorities."

But Mr Corbyn retorted that he could not deliver on what he was promising.

"That idea that the Prime Minister Boris Johnson' deal can be dealt with and finished by the end of January is such nonsense," he said.

"What he is proposing is a trade deal which will take at least seven years to negotiate whilst at the same time saying he will negotiate a special trade deal with the European Union.

"The two things are actually incompatible."

Mr Corbyn defended Labour's strategy to negotiate a new deal with the EU within three months of taking office and then put it to voters in a referendum within six months.

However he was taunted by Mr Johnson over his refusal to say which way he would vote, saying: "Are you going to campaign for Leave or Remain?"

The Labour leader hit back accusing him of conducting secret meetings with the US about opening up the NHS to American companies in a future trade deal.

Mr Johnson, however, said the claim was "an absolute invention".

"It is completely untrue. There are no circumstances whatever in which this Government or any Conservative government will put the NHS on the table in any trade negotiation," he said.