Tim Farron was confronted on the campaign trail by a Theresa May supporter, who accused him of believing Leave voters are racist.

Mr Farron strongly denied the charge, insisting: “Loads of my mates voted Leave, I don’t think they are racist,” – prompting 65-year-old Malcolm Baker to reply: “Yes you do.”

The finger-pointing pensioner added: “I voted Leave and I’m proud to have voted Leave and I knew what I was voting for.”

Mr Farron, visiting Oxfordshire, then asked him: “Have you got grandchildren? Are you proud that they will inherit a poorer, less powerful, less secure country?”

But Mr Baker stood his ground, saying: “I’m proud that they will be coming out of Britain, err, out of Europe and that we will have our own destiny and not have people telling us are going to pay £100bn to get out.”

Laying bare the dangers of politicians coming face-to-face with angry voters, he added: “If that’s your policies, I hope you only get six seats!”

Mr Baker then told journalists: “I have always voted Labour, but I will be voting for Theresa May,” – prompting a shout from a bystander of ‘You f***ing idiot’.

It was reported today that the EU will expect Britain to pay a higher-than-expected divorce bill of €100bn, although Michel Barnier, the European Commission’s Brexit negotiator, declined to confirm the figure.

A Lib Dem spokesman said it was Labour that should be alarmed by the encounter – and sought to make a virtue of Mr Farron's refusal to hide from voters.

“Tim today was out meeting voters today, unlike Theresa May, like he did yesterday and the day before," he said. "That exchange should have worried Labour, as a life-long Brexiteer voter is leaving them.