U.K. Prime Minister Theresa May lost control over the warring factions within her government as the Cabinet descended into open conflict over her Brexit plans at an angry meeting on Tuesday.

According to people familiar with the matter, seven senior pro-Brexit ministers spoke out against a proposal that could allow the U.K. to stay inside the European Union’s tariff regime indefinitely.

May was said to have reacted angrily to the intervention during the meeting with what was described as her trademark “death stare.” Then other ministers launched a counter attack and warned that the U.K. will crash out of the EU with no deal unless she is able to compromise.

May lurching from crisis to crisis has been the defining narrative of her time in office. What’s changed is that the prime minister does seem to have reached the point where as the end of Brexit nears, it’s increasingly apparent her biggest struggle is at home rather than in Brussels.

“May is in her most perilous position to date domestically,” said Eurasia Group Managing Director Mujtaba Rahman. There is “intense speculation that euroskeptic MPs will soon force a vote of confidence in her as Tory leader.”

The infighting in the British government escalated at a critical time in the Brexit process, with time running out and talks still stuck on the thorny question of how to avoid customs border checks at the land frontier between Ireland and the U.K.

A summit of EU leaders broke up last week with no agreement and plans for a special gathering to sign off on the terms of the divorce next month have been shelved. On the EU’s part, preparations are being stepped up to cushion the impact of a chaotic split in case negotiations fall apart, according to people familiar with the issue.

Tuesday’s weekly Cabinet meeting in May’s Downing Street offices was described as punchy, impassioned and containing fireworks by several people familiar with the discussions, who declined to be named discussing private conversations.

Foreign Secretary Jeremy Hunt is said to have led the assault on May’s plan, with support from Home Secretary Sajid Javid, and fellow cabinet ministers Penny Mordaunt, Michael Gove, Andrea Leadsom, Geoffrey Cox and Liz Truss.

The Crux

The group demanded a fixed end-date to the so-called backstop guarantee to avoid a hard border on the island of Ireland, or at least some kind of mechanism for the U.K. unilaterally to escape the arrangement if necessary.

For these ministers, the idea that Britain should be tied into the EU customs regime potentially forever is a betrayal of the vote to leave the bloc and would be a loss of national autonomy. They argued that a backstop without any meaningful limits would not pass through Parliament, a view reinforced by May’s chief whip, Julian Smith.

But four other cabinet ministers -- including Education Secretary Damian Hinds and May’s de facto deputy, David Lidington -- hit back on the other side of the argument. They said the EU will never agree to a time limit on the Irish border backstop and the government should not be imposing unrealistic red lines on the negotiations that will destroy the chances of getting a deal.

Missed Speech

According to the Financial Times, some ministers also reacted in disbelief when they were told that in the event of a no-deal Brexit, the government plans to charter commercial ships to bring in emergency medicines and food.

The Cabinet argument ran on so long that Gove, the environment secretary, missed a speech he had been due to deliver to British and Irish parliamentarians across the road. In his absence, the audience occupied themselves with a polite discussion of moments of unity in the two countries’ history.

On Wednesday, May will face another showdown with her party, this time confronting a gathering of the 1922 Committee of rank-and-file Tory members of Parliament, who will challenge her strategy afresh. Many of them were angry last week after she floated the idea of keeping the U.K. bound to EU trade terms for longer than previously planned.

May survived a revolt on Monday when some of her strongest Brexit critics backed down. There are also conflicting reports of whether a plot to oust her will have enough support to succeed. But European leaders watching developments in London are concerned May won’t be able to get a deal agreed.

EU nations now see the prospects of a special Brexit summit being called next month to seal the divorce terms as highly unlikely. The bloc is stepping up preparations for a potential cliff-edge withdrawal, people familiar with the discussions said.

Even if there’s progress in negotiations with the U.K. over the coming weeks, the EU’s 27 remaining governments see few chances of holding a leaders’ meeting in November, two officials said. The officials asked not to be named, as the information isn’t in line with the bloc’s official position that it stands ready to convene a special Summit when talks have advanced and a deal is within reach.

One of the officials said that the EU isn’t confident that May commands enough support in Parliament for the compromises required, and European governments want to wait and see if the Irish backstop proposal triggers a mutiny in the vote over next year’s U.K. budget.