In a dramatic plot twist, John Bercow has blocked Theresa May from bringing back her Brexit deal for a third meaningful vote unless the government makes “substantial changes”.
He cited an ancient 400-year-old Commons rule that blocks parliament being forced to vote on the same issue repeatedly in a short space of time.
It comes after May’s Brexit deal was rejected twice by MPs, with the government suffering its biggest defeat in 95 years when deal was put before parliament for the first time.
Bercow’s decision is major blow to the PM, who planned to pile pressure on MPs to change their minds with a third vote this week, and possibly a fourth before 29 March Brexit deadline.
The BBC’s political editor Laura Kuenssberg admitted that Bercow’s announcement was "massive".
And other politicians and commentators agreed that the speaker's announcement is likely to shake up the Brexit process.
But not everyone was so sure.
Many people were delighted with the speaker's decision, which could be a major setback for the PM who planned to push through her deal this week.
Many used the news to point out the need for a People's Vote.
Others pointed out that this is what you get when you try to mess with a 400-year-old democracy.
Bercow said he had allowed last week’s second vote – which suffered the fourth-worst government defeat in history – because it contained “legal changes the government considered to be binding”.
But he told MPs:
If the government wishes to bring forward a new proposition that is neither the same nor substantially the same as that disposed of by the House on 12 March, this would be entirely in order.