Meeting in Strasbourg, MEPs backed a resolution rejecting parallel talks on the UK’s departure from the EU and its future trading relationship, and taking note of Scotland’s 62% vote in favour of remaining in the bloc.
European Commission’s president Jean-Claude Juncker and chief Brexit negotiator Michel Barnier told the session of the European Parliament that the EU could not deal with its future relations with the UK until the terms of withdrawal, including a possible £50 billion exit bill, were “fully resolved”.
Mr Barnier said: “We do not seek to punish the United Kingdom, we are simply asking the United Kingdom to deliver on its commitments and undertakings as a member of the European Union.”
Mr Farage was rebuked for claiming that MEPs were “behaving like the mafia”, with the parliament’s president, Italian Antonio Tajani, telling the former UKIP leader to retract the “unacceptable” comment.
Mr Farage said he would instead brand them “gangsters” and labelled EU demands for payment of outstanding budget commitments by the UK as “a kind of ransom payment”.
Mr Farage warned the EU not to drive too hard a bargain over the UK’s divorce settlement, and called the demands “vindictive” and “nasty”.
“If you wish to have no deal, if you wish to force us to walk away from the table, it is not us that will be hurt,” he said.
Mr Barnier replied: “In fact, Mr Farage, all we are doing is settling the accounts. No more and no less.”
David Martin, the UK’s longest-serving MEP, said the UK could “cease to exist” if Theresa May pushed ahead with a “hard Brexit” outside the European single market.
Speaking to the BBC ahead of the debate, he said his stance on Scottish independence had shifted following the Brexit vote.
“I voted for two unions: I voted to remain in the United Kingdom, I voted to remain in the European Union - that choice has been removed from me.” Asked how he would vote in a second referendum, Mr Martin said: “In truth, I have no idea at the moment, there are too many factors to weigh up.”
A Scottish Labour spokesman said it would “never support independence”. But Tory MSP Miles Briggs said: “Kezia Dugdale now has to either completely distance herself from these comments by her own MEP, or concede that Labour is all over the place on the constitution.”
The European Parliament, which has a veto on the final Brexit deal, backed the resolution by 560 to 133.