Boris Johnson has attacked Jeremy Corbyn on Brexit ahead of their final TV debate of the election campaign, accusing him of planning to “fiddle” a second referendum.
The prime minister has written to Mr Corbyn, claiming Labour would give two million EU nationals the vote, making it much harder for Leave to win.
But ahead of the debate, Mr Johnson has been attacked by the veteran BBC broadcaster Andrew Neil on his show for refusing to commit to an interview with him.
He said if the prime minister is expected to face the likes of Donald Trump and Vladimir Putin then he should be able to sit down for a half-hour interview with him.
Referring to interviews he has conducted with party leaders during the election campaign, Mr Neil said: “We’ve always proceeded in good faith that the leaders would participate.
“And in every election they have. All of them. Until this one.”
And he told the prime minister: “It is not too late. We have the interview prepared. Oven-ready, as Mr Johnson likes to say.
“The theme running through our questions is trust, and why at so many times in his career, in politics and journalism, critics and sometimes even those close to him have deemed him to be untrustworthy.”
Mr Johnson’s attack on Mr Corbyn is almost identical to an allegation made by his controversial adviser Dominic Cummings last week, confirming that Mr Cummings is masterminding the prime minister’s Brexit strategy.
And the tactic of writing to Mr Corbyn and challenging him on his Brexit policy was used by Mr Johnson ahead of the first TV debate between the two leaders on ITV last month.
In that debate, which a snap YouGov survey suggested voters backed Mr Johnson by 51% to 49%, the Labour leader refused nine times to say whether he backed Leave or Remain, according to the Tories.
The second TV debate, hosted by the BBC, comes less than a week before next Thursday’s election and with the latest opinion polls suggesting the Conservatives have a 10-point lead over Labour.
Although the Tories’ poll lead has narrowed slightly during the election campaign, the hour-long BBC debate is almost certainly Mr Corbyn’s last chance to achieve a major boost in Labour support.
In his latest letter to the Labour leader, Mr Johnson writes: “Your policy is to cancel the result of the last referendum and to hold another one.
“You have made clear that you oppose an Australian-style points system and you will not only continue ‘free movement’ with the EU but your policy is extend it to the entire world.
“This is a sly attempt to undermine the result of the 2016 referendum, and is profoundly undemocratic. No true democrat, even the most ardent supporter of Remain, could support your attempt to undermine the result of a democratically expressed vote.
“I urge you in the strongest possible terms to reconsider this policy before the election on Thursday. Cancelling the result of the 2016 referendum is dangerous enough.
“Your approach has already done serious harm to trust in democratic politics and cancelling the result of the previous referendum before it has even been implemented will do more damage.
“But your policy of giving millions of foreign citizens the vote in order to overturn the referendum would create incredible bitterness that might take decades to repair.
“Imagine how people will feel if the biggest democratic exercise in our history is overturned because you gave two million EU citizens the power to reverse Brexit. It would alienate millions who already feel disenfranchised and ignored by our political system.”
The Conservatives claim the Labour manifesto commits to giving the vote to “all UK residents”, which would mean extending the franchise to all voting age EU nationals with residency in the UK, adding two million people to the electorate.
According to the Tories, academic research suggests 90% of these new voters would very likely back Remain, meaning Leave could need to win nearly 500,000 more votes than it did in 2016 to win again.
The “cheat” claim was first made by Mr Cummings in a blog, in which he wrote: “If Boris doesn’t get a majority, then Corbyn will take control of No 10 on Friday 13th in alliance with Sturgeon plus the Liberal Democrats.
“And if this Corbyn-Sturgeon alliance takes control, their official policy is to give millions of EU citizens the vote in the second referendum.
“They don’t plan to lose again and they’ve literally written into their manifesto that they will cheat the second referendum.”
Responding to Mr Johnson’s letter to Mr Corbyn, Cat Smith, Labour’s shadow minister for voter engagement, did not deny her party plans to give a vote to EU nationals in a second referendum.
“The Labour Party believes in democracy,” she said.
“We welcome securing a new and better Brexit deal, and putting it back to the people to have the final say.
“If Boris Johnson had any confidence in his own deal, he would have let it be scrutinised by parliament, and then put it back before the people for their verdict.”