Boris Johnson news - live: PM forced to seek another extension from EU after Letwin amendment delays crucial Brexit vote

MPs have backed a rebel amendment that would throw Boris Johnson's Brexit plans into disarray by forcing him to seek an extension from the EU.

As hundreds of thousands of protesters took to the streets to call for a Final Say referendum, MPs used a historic Saturday sitting to approve amendment from Sir Oliver Letwin, which withholds Commons approval until legislation to ratify the Brexit deal has passed.

The prime minister insisted he “would not negotiate a delay” – despite being legally compelled to do so – prompting speculation No 10 might try to get around a law forcing the PM to send a letter to the EU asking to delay Brexit beyond the 31 October deadline.