BORIS Johnson WILL request a Brexit extension if no withdrawal agreement is reached by October 19, documents read out at Scotland's highest court have revealed.

The Prime Minister and senior Tory ministers have hinted that he may attempt to circumvent legislation to avoid delaying Brexit. Johnson has repeatedly insisted the UK will leave by October 31 – “deal or no deal”.

But Government documents submitted to the Court of Session say the Prime Minister will send a letter asking for an extension to Article 50.

Downing Street refused to comment after the documents were read out during the case at the Court of Session.

The Prime Minister has publicly said "we will obey the law, and will come out on October 31" in any event, without specifying how he would achieve the apparently contradictory goals – fuelling speculation that he had identified a loophole to get around the Benn Act.

READ MORE: Joanna Cherry in fresh legal battle against Boris Johnson

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

Maugham told Sky News: "What we learned today is that the Prime Minister has promised the court, in his own name, that he will ask for an extension under the Benn Act if the conditions are satisfied, in other words if Parliament has not before October 19 agreed a withdrawal agreement.

"He's also promised the court that he will not frustrate the Benn Act by which is meant that he will not send two letters, one saying 'can I have an extension', the other saying 'please don't give me one', he won't collude with foreign governments to attempt to persuade those foreign governments to veto an extension."

The National: Joanna Cherry

Meanwhile, a Scottish judge said it would be "unprecedented" for an official to exercise powers to sign the Article 50 extension on behalf of Boris Johnson.

The Court of Session's Inner House heard the unique power of nobile officium – which would allow a court official to sign the letter – has never been used over a prime minister.

READ MORE: Boris' Brexit plan 'not remotely acceptable' according to MEPs

Lord Drummond Young said: "In the circumstances of this case it is unprecedented. There's a question of competence."

In an earlier statement, Cherry said: "Like much of what Boris Johnson says, there is a gulf of truth between the obvious facts of the matter and what he and his Government have been saying.

"He cannot be trusted, and this court action is about ensuring he abides by the law.

"If Boris Johnson tries to defy the law and defy both the Holyrood and Westminster parliaments by crashing out of the EU without a deal - then we are calling on the Scottish courts to uphold the law."