The High Court has decided that the first stage of a legal challenge against the deal between the Conservative government and the DUP will initially be heard at the Divisional Court - a special sitting of the High Court - on October 26.

The Divisional Court is not a separate branch of the High Court, but rather refers to a sitting where there are at least two judges.

This challenge is at the first stage of a two-stage process that a judicial review application must pass through before getting to the judicial review stage.

When taking a judicial review, the challenging party must first apply for permission to apply for a judicial review.

It is unusual for this stage of the review process to be dealt with in an oral hearing, and would more commonly be processed in writing.

The challenge is being taken by Green party politician Ciaran McClean, who stood for the party in West Tyrone at the last General Election, and alleges that the agreement is in breach of the Good Friday Agreement.

Mr McClean is being represented by London law firm Edwin Coe LLP, which represented one of the clients in the successful litigation that determined the British government did not have the power to invoke Article 50 without the approval of Parliament.

It is alleged that the confidence and supply agreement breaches the section of the Good Friday Agreement that specifies the British government is required to act in Northern Ireland "with rigorous impartiality on behalf of all the people in the diversity of their identities and traditions".

It is also alleges that the agreement breaches the Bribery Act 2010.

Speaking about a decision to convene a special sitting of the High Court David Green, partner at Edwin Coe, said: "We believe the Court has concluded correctly and in accordance with our submissions that this is a matter of such constitutional importance that even the application for permission should be dealt with by a Divisional Court as was the Article 50 application."

The decision was also welcomed by Mr McClean, who said: "I am extremely happy that the Court has decided that the issues here are of such magnitude that a special court must be convened to hear what we say."

Belfast Telegraph