British MPs have voted to potentially delay Brexit further, with an amendment that delays the approval of Boris Johnson's deal with the EU until implementing legislation has been ratified.
It is a further defeat for the Prime Minister, who subsequently called off a vote for his deal, which was scheduled today on a historic Saturday sitting in Parliament.
Meanwhile, hundreds of thousands of anti-Brexit protesters descended on Westminster, calling for a second referendum, or the withdrawal of Article 50.
Boris Johnson does not have a majority in parliament, and he needs around 320 MPs to back his deal, which he said he will now bring before Parliament next week.
If his deal does not pass, legislation requires Johnson to write to the EU chief Donald Tusk and ask for a three-month extension.
You can watch what was another historic day in Parliament in the video player, above, or scroll through the day's key developments in our live blog below.