London (CNN) Next week, Britain's House of Commons will vote on whether Prime Minister Theresa May's Brexit deal should go ahead. Given that May's Conservative party has no overall majority and too many of her own members of parliament are against it, she was already braced for defeat in that vote. But after extraordinary scenes in the Commons on Tuesday evening, that likely defeat could also mean the end of her premiership.

In little more than an hour on Tuesday, the government suffered three defeats on its Brexit plans . The first two were embarrassing enough: MPs voted that the government was in contempt of parliament, the first time that's happened in British history. By refusing to publish in full the legal advice on the Brexit deal agreed with the European Union last month, ministers were found to have breached the sovereignty of parliament -- and parliament has fought back and reasserted its control.

The third defeat, while more technical, was still hugely significant because it means that next Tuesday, MPs from all parties can decide not only to reject May's deal but instruct the government on what to do next.

Until now, the Prime Minister has warned MPs that voting down her Brexit plans will mean a no-deal departure from the EU by default. That scenario is relished by some hardline Brexiteers who want out of the EU at any cost. But it has spooked financial markets, businesses and the Bank of England, who have warned that it will come at a severe economic price to Britain.

But Tuesday's scenes made one thing clear: MPs are likely to use their new-found power to block a no-deal outcome. The hardest of all Brexits seems off the table.

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