British Prime Minister Boris Johnson has reiterated his intention to ensure that the UK leaves the EU on 31 January 2020 during his first TV debate of the election campaign with Labour leader Jeremy Corbyn.

Mr Corbyn began proceedings by saying he would deliver the result of a second referendum on Brexit.

He dismissed Mr Johnson's pledge to "get Brexit done" by the end of January as "nonsense".

 "The idea that the Prime Minister's deal can be dealt with and finished by the end of January is such nonsense," Mr Corbyn said.

He said the prime minister was proposing a trade deal with the US that would take "at least seven years to negotiate", while also holding talks with the EU on trade, claiming: "The two things are actually incompatible."

Mr Johnson said he had a deal that was "oven ready" and he would take the UK out of the EU in 2020.

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."

Asked about the threat to the union that Brexit poses, Mr Corbyn said Mr Johnson's deal with the EU was damaging to the UK.

Mr Johnson defended his deal and said the people did not know what kind of deal Mr Corbyn would do.

Mr Corbyn said the agreement that the prime minister put to parliament was about creating a border down the Irish Sea having promised the DUP he would never do that.

Brexit Party leader Nigel Farage tweeted: "If the Union is so important to Boris, why did he put a border down the Irish Sea?"

Mr Johnson later challenged the Labour leader about a future referendum, asking: "Are you going to campaign for Leave or Remain?"

Mr Corbyn replied: "I want to bring people together, therefore there will be a referendum in which that decision will be made by the British people and our government will abide by that decision."

In his closing remarks, Mr Corbyn urged viewers to register to vote in a "once-in-a-generation election".

He added: "This is a once-in-a-generation election to end privatisation and give the National Health Service the funding it needs. To give people the final say and get Brexit sorted.

"To tackle the climate emergency that threatens our futures. To invest good jobs in every region and nation of our country.

"I ask that you vote for hope and vote Labour on December 12."

Summarising, Mr Johnson accused Mr Corbyn of being "unfit" to be prime minister.

He added: "Mr Corbyn, you've heard tonight, cannot answer the fundamental questions. Is he for Remain or Leave and what price would he pay to secure Nicola Sturgeon's support to enter Number 10?

"If he can't answer those questions tonight, I don't think he's fit to lead our country."