Boris Johnson will seek a Brexit extension from the EU if no new deal is agreed by Oct 19, court documents have revealed.

The legal memo states that the Government will abide by the terms of the Benn Act and send a letter asking for more time to Brussels.

It also says it will not "frustrate" the law, suggesting the Prime Minister will not ask member states to veto an extension request.

Aidan O'Neill, for the petitioners, told the Court of Session that while Mr Johnson now said he would obey the law, that position contradicted previous claims saying he would not obey the Benn Act.

He added that a sworn statement to the court from the Prime Minister could explain which position was “true”, but there was none.

Mr O'Neill said the Prime Minister had been discussing "sabotaging" the Benn Act in media reports.

Scotland’s highest civil court will hear two cases in the space of five days that could compel Mr Johnson to extend the negotiations.

A hearing has now begun in the Outer House of the Court of Session on whether the Prime Minister can be forced to extend Article 50.

The legal action - led by businessman Vince Dale, SNP MP Joanna Cherry QC and Jolyon Maugham QC - will ask the court to require Mr Johnson to seek an extension to avoid leaving the EU without a deal.

On Tuesday the team will go to the Inner House to ask the Scottish judges to use the unique power of “nobile officium” to empower a court official to sign the extension letter if the Prime Minister refuses to do so.

It comes as Rory Stewart has announced his intentions to run to be Mayor of London as an independent, after announcing his intention to stand down at the next election.

He is standing is a bid to break "the suffocating embrace of our dying party politics" and promises to "listen to the people".