European President Donald Tusk slammed people who promoted Brexit, warning that a “special place in hell” await them when they die.
The vile comments were made after talks with Irish premier Leo Varadkar in Brussels.
BBC News reports: Brexit-backing MPs reacted with anger to the comments, accusing Mr Tusk of “arrogance”.
Downing Street said it was a question for Mr Tusk “whether he considers the use of that kind of language helpful”.
The prime minister’s official spokesman said: “We had a robust and lively referendum campaign in this country. In what was the largest democratic exercise in our history people voted to leave the EU.”
He added that everyone should now focus on delivering that.
Mr Tusk’s Twitter account tweeted his comments immediately afterwards:
And at the end of their press conference, Mr Varadkar was picked up by the microphones telling Mr Tusk: “They’ll give you terrible trouble in the British press for that.”
Mr Tusk nodded at the comment and both laughed.
Brussels officials were quick to clarify Mr Tusk’s remarks, stressing to BBC correspondent Adam Fleming that the Brexiteers’ special place in hell would be for when they are dead and “not right now”.
Jean-Claude Juncker tried to laugh off the comments at a later press conference with Mr Varadkar, saying the only hell he knew was doing his job as the president of the European Commission.
And Guy Verhofstadt, the European Parliament’s chief Brexit negotiator, referencing Mr Tusk’s comments, later tweeted: “Well, I doubt Lucifer would welcome them, as after what they did to Britain, they would even manage to divide hell.”
But leading Brexiteers in the UK took to social media to express their anger at Mr Tusk’s remarks.
Former UKIP leader, and now an independent MEP, Nigel Farage, tweeted: “After Brexit we will be free of unelected, arrogant bullies like you and run our own country. Sounds more like heaven to me.”
Commons leader Andrea Leadsom, who also campaigned for Britain’s exit from the EU, said Mr Tusk should apologise for his “disgraceful” and “spiteful” comments.
“I’m sure that when he reflects on it he may well wish he hadn’t done it,” she told BBC Radio 4’s World at One.
The Democratic Unionist Party’s Brexit spokesman Sammy Wilson said: “This devilish Euro maniac is doing his best to keep the United Kingdom bound by the chains of EU bureaucracy and control.
“It is Tusk and his arrogant EU negotiators who have fanned the flames of fear in an attempt to try and overturn the result of the referendum.”
But Sinn Fein President Mary Lou McDonald backed Mr Tusk, arguing that it was the position of “hardline” Brexit-supporting MPs like Boris Johnson and Jacob Rees-Mogg that was “intemperate” and “untenable”.
And Labour MP Ben Bradshaw, who supports another EU referendum, said Mr Tusk was “absolutely right” and it was “painful” for leading figures in the Leave campaign, such as Boris Johnson and David Davis, “to have the truth pointed out to them”.
Theresa May – who supported the UK staying in the EU during the 2016 EU referendum but has always insisted that Brexit must be delivered because that was what people voted for – is due to arrive in Brussels on Thursday to seek legal changes to the withdrawal deal she signed with the EU. She hopes these changes will help her get it through the UK Parliament.
Meanwhile, the government is likely to publish a new employment bill before the next vote on Mrs May’s deal, with the aim to maximise support for it from Labour MPs.