The UK will request a Brexit delay, in another bruising defeat for Boris Johnson

The UK is firmly on track to delay Brexit for the third time, after an amendment tabled by Oliver Letwin-a former Conservative MP booted out of the party by prime minister Boris Johnson- passed in Parliament today by a vote of 322 to 306. The cleverly devised amendment formally withholds approval of Johnson's new Brexit deal until legislation implementing the deal is enacted, and therefore triggers the earlier Benn Act that forces Johnson to request a delay from the EU until Jan. 31.

Conservative MPs have vacated Parliament, which is now expected to hold a vote on the deal next week. Letwin plans to vote for the deal, but wants to eliminate the chance of a no-deal Brexit.

The leaders of the opposition Labour party, Scottish National Party, and the Liberal Democrats backed the amendment. A number of independent Tory MPs also supported it, as did Northern Ireland's Democratic Unionist Party that is part of the Conservative minority government.

Johnson's Brexit deal was a major concession to the EU, and had scrapped the controversial Irish backstop in his predecessor Theresa May's agreement that would have tied the UK in its entirety to the EU's customs union until a wider free-trade agreement was reached. Instead, the government agreed to in effect create a customs border between Northern Ireland and the rest of the UK in the Irish sea.

The full text of the Brexit agreement was released on Thursday, but no government economic assessment has been released. The UK in a Changing Europe think tank estimates that Johnson's deal would leave GDP between 2.3% to 7% lower over the next 10 years, a gloomier economic forecast than May's earlier deal.

The defeat extends Johnson's losing streak in Parliament, in which the UK prime minister has not won a single vote since becoming prime minister in July. It also further increases the likelihood that a general election, and possibly a second referendum on the UK's membership in the EU, will follow.

Meanwhile, hundreds of thousands of Brits marched today in London for another People's Vote rally, to ask for a second referendum. "Remain" has edged out "Leave" across polls in recent months, helped in part by "Bregret" and previous non-voters who overwhelmingly favor staying in the EU and might vote this time around.