MPs have won a key parliamentary vote paving the way for a Commons bid to secure a second referendum on Saturday.

Ex-Tory backbencher Sir Oliver Letwin led a successful attempt to allow backbench MPs to amend Boris Johnson's Brexit plans, in a knife-edge vote that passed by 287 votes to 275.

MPs also approved a rare Saturday sitting to scrutinise Mr Johnson's new plan - but the government's proposal for a short debate on a motion to either "approve the deal or approve a no-deal Brexit" were derailed by the backbench victory.

The move now clears the way for pro-EU MPs to force a vote on a second referendum, by tacking on an amendment calling for another public vote on the prime minister's Brexit blueprint.

Sir Oliver said the plan would allow MPs to move any amendment to the government's proposal and for them to be voted upon, if selected by Speaker John Bercow.

He suggested that it could close a loophole in the so-called Benn Act - which requires the PM to seek a Brexit delay if he does not have a deal by 19 October. The law only compels the PM to seek an extension if MPs fail to pass a motion.

Sir Oliver told MPs: "That will enable those of us, like me, who wish to support and carry through and eventually see the ratification of this deal, not to put us in the position of allowing the government off the Benn Act hook on Saturday, but only at a time when the bill has been taken through both Houses of Parliament and legislated on."

Jacob Rees-Mogg, the Commons leader, said Mr Johnson would make a statement at 9.30am on Saturday and take questions about his talks with the EU.

He suggested MPs would be offered the chance to either approve a deal or approve a no-deal Brexit.

The Brexiteer said he would support the plan, as the prime minister deserved credit for his "remarkable success in a deal that all of us can support".

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He said: "It is a really exciting and positive deal. It removes the undemocratic backstop. It is a huge advance for the whole of the United Kingdom.