Michel Barnier, the European Union’s chief Brexit negotiator, has accused Nigel Farage of telling lies during the referendum campaign.

Mr Farage denied he lied and challenged Mr Barnier to, “Tell me one thing I said that was untrue”.

Mr Barnier was speaking in Zagreb, Croatia at a “citizens dialogue” ahead of European elections later this month, where Mr Farage’s Brexit Party are expected to triumph. He warned that the MEP and former Ukip leader hopes to destroy the EU.

Mr Barnier said on Wednesday that the British people were not told of the risks Brexit would pose to peace in Ireland before they voted to leave in 2016.

In contrast, he said, the EU had put the Irish question on the table since the beginning of the Brexit negotiations.

Mr Barnier said, “Certain people like Mr Farage did not tell the truth in the referendum campaign.”

“It is almost a banality but when one make an electoral campaign one must tell people the truth and that was not the case for certain people during the referendum campaign in Britain.”

“They did not evoke the consequences of Brexit before the citizens,” he added, "They practically did not speak about Ireland at the moment of referendum.”