LONDON — Good for Donald Tusk. Just when Brexit renegotiations were getting a bit dull, the president of the European Council livened things up by suggesting there was “a special place in hell” for “those who promoted Brexit without even a sketch of a plan of how to carry it safely.”

That got everyone’s attention, especially in London.

Tusk was speaking at a news conference in Brussels following a morning meeting with the Irish Prime Minister Leo Varadkar. The two were discussing how to preserve an open border in Ireland after Britain leaves the European Union on March 29.

Brexit is in trouble, as the British Parliament, in a crushing humiliation, voted down the deal struck between Prime Minister Theresa May and her European counterparts.

Now May is headed back to Brussels on Thursday to ask the Europeans to help her get the deal through Parliament by changing what is called the Irish backstop, an insurance policy agreed by both sides that would keep the border open between Northern Ireland (part of the United Kingdom) and Ireland (part of the E.U.).

In the news conference, Tusk said he was trying to forge ahead with the British but also warned that European leaders were preparing for the “possible fiasco” of a no-deal Brexit.

Britain is hurtling toward crashing out of the European Union in 51 days with no deal — and no trade agreements, no transition period. This could cause serious economic havoc.

The Europeans have hoped that Britain would, could, might ultimately decide not to divorce, but reconcile. Tusk has stressed that in the past. But on Wednesday, he seemed ready to move on.

“I have always been with you with all my heart, but the facts are unmistakable,” Tusk said. “At the moment the pro-Brexit stance of the U.K. prime minister and the leader of the opposition rules out this question. Today there is no political force and no effective leadership for remain.”

But Tusk was firm when it came to protecting the Good Friday peace accord, which ended 30 years of sectarian violence in Ireland and relies on an open border to ease tensions and bolster good will.

“There is no room for speculation here. The E.U. is first and foremost a peace project. We will not gamble with peace or put a sell-by date on reconciliation,” Tusk said.

Regarding the special place in hell line, a representative for the British prime minister told reporters, “I think it is a question for Donald Tusk as to whether he considers the use of that kind of language to be helpful.”

As the news conference in Brussels was winding down, Varadkar was picked up by a hot mic telling Tusk: “They’ll give you terrible trouble, the British, for this.” It was unclear whether he meant his words or his negotiating position.

No matter, Tusk and Varadkar both laughed.

Reaction, as they say, was swift and furious from the Brexiteers.

The Brexit chief for Northern Ireland’s Democratic Unionist Party, Sammy Wilson, branded Tusk a “devilish, trident wielding, euro maniac.”

Nigel Farage, the former leader of the U.K. Independence Party, whose rise was partly responsible for convincing former prime minister David Cameron to stage the June 2016 Brexit referendum, replied that Tusk was an arrogant bully and his version of hell sounded like heaven to him.

While some were pushing back at Tusk, others believed his remarks — and the impasse they represent — shine a poor light on May, who can’t seem to close this deal.

The former No. 2 at 10 Downing, George Osborne, now a newspaper editor, tweeted, “negotiations going well then ...”

The British political press labeled Tusk’s remarks incendiary.

But it was not the first time the Europeans have complained about Brexit.

Tusk has dropped provocative lines before. In January, he hinted about the possibility of Britain staying in the E.U., tweeting: “If a deal is impossible, and no one wants no deal, then who will finally have the courage to say what the only positive solution is?”

In the months following the Brexit vote, the European Commission chief, Jean-Claude Juncker, blamed Brexit on “40 years of lies” by British politicians.

French President Emmanuel Macron once said Brexit was “a choice pushed by those who predicted easy solutions . . . they are liars, they left the next day so they didn’t have to manage it.”

For weeks, they have been begging May to tell them — exactly — what she wants amended in the withdrawal agreement, so that it can pass her divided House of Commons. May, publicly, has said she needs “alternative arrangements” to protect an open Irish border that does not involve keeping Britain trapped in an E.U. customs regime forever. Some have suggested new technologies might come to the rescue.

Talks, such as they are, continue.