Legal action aimed at forcing the Prime Minister to send a letter requesting a Brexit extension has been dismissed at the Court of Session.

Parliament last month passed legislation designed to compel Boris Johnson to delay the UK's exit beyond October 31 if no withdrawal agreement with the EU is reached by October 19.

However, petitioners who believe Number 10 cannot be trusted to abide by the law launched legal action at the Court of Session which would force Johnson to seek an extension.

In the judgment published on Monday, Lord Pentland said both the Prime Minister and the UK Government had given "unequivocal assurances" that they would comply with the legislation, known as the Benn Act.

He cited documents submitted to the court's Outer House which show Johnson accepts he must send a letter to the EU requesting an extension to Article 50.

"As a result the judge stated: "I am not persuaded that it is necessary for the court to grant the orders sought or any variant of them."

But Lord Pentland warned that if Mr Johnson failed to comply with the legislation, it could damage the "mutual trust" that exists between the courts and the politicians.

He stated: "I approach matters on the basis that it would be destructive of one of the core principles of constitutional propriety and of the mutual trust that is the bedrock of the relationship between the court and the Crown for the Prime Minister or the government to renege on what they have assured the court that the Prime Minister intends to do."

Businessman Dale Vince, SNP MP Joanna Cherry QC and Jolyon Maugham QC launched the legal action over fears Mr Johnson would attempt to thwart the Act.

Orders sought included stopping the Prime Minister from "frustrating" the will of the Act and mandating him to send the request.

Mr Johnson, Downing Street sources and Cabinet ministers have repeatedly asserted the country will leave on October 31 regardless.

However, documents submitted to the court on behalf of the Prime Minister on Friday revealed he accepted he must send the letter under the terms set out in the legislation.

It also shows Number 10 accepts it cannot attempt to "frustrate" it.

Andrew Webster QC, representing the UK Government, argued this should be enough for the court to be satisfied the Mr Johnson would comply with the legislation.

He added that imposing any orders could "ruin" the negotiating strategy with the EU.

Aidan O'Neill QC, representing the petitioners, claimed Mr Johnson's previous statements go against what he has said to the court through the documents.

He referred to promises made by the Prime Minister that he would rather be "dead in a ditch" than send a letter requesting an extension, and that the UK will leave on October 31 "do or die".