There will be no delays in dealing with a fresh legal challenge to the £1.2bn A5 road upgrade, a High Court judge pledged today.

As a group of residents and landowners commenced judicial review proceedings against the dual carriageway scheme, Mr Justice McAlinden confirmed he is ready to clear his diary to hear the case.

“It’s important we get this dealt with as quickly as possible,” he said.

“There will be no delay in relation to this matter… I will make sure I’m free to deal with it.”

The long-awaited upgrade to the main corridor between Derry and Aughnacloy in Co Tyrone was given the go-ahead by Infrastructure Minister John O’Dowd last month.

Work on the first phase of the 53-mile stretch of road is currently due to begin early next year.

With 57 deaths recorded on the A5 since 2006, campaigners have demanded improvements to be carried out.

The scheme, which forms part of a proposed key cross-border business route linking Dublin and the north west, has already been held up by previous legal actions.

An umbrella body of landowners, farmers and supporters known as the Alternative A5 Alliance successfully challenged earlier decisions to approve the project in 2013 and again in 2018.

Fresh proceedings have been brought by nine individuals against the Department for Infrastructure.

Niall McKenna, chair of the A5 campaign group Enough is Enough, at the Royal Courts of Justice in Belfast. Image: Pacemaker

They claim the decision to begin the initial phase breaches legislative goals for cutting greenhouse gas emissions in Northern Ireland.

The Climate Change (NI) Act 2022 contains a series of interim targets moving towards achieving net-zero emissions by 2050.

According to lawyers representing the group, approving part of the A5 scheme is irrational and an unlawful breach of the Act.

“No reasonable authority could have come to the conclusion… that there was sufficient information to demonstrate that mandatory emission reduction targets under the Act would still be met if the A5 scheme were approved,” legal papers contend.

Further grounds of challenge allege: a breach of planning regulations; a breach of habitats regulations by failing to take an appropriately precautionary approach to the impact on the Tully Bog conservation area; a failure to further consult the public; and a breach of the group’s Article 8 human rights.

The court heard that the applicants are seeking a protective costs order which would impose a cap on any legal bill.

None of them attended the preliminary hearing to timetable the case.

Paul McLaughlin KC, for the Department, made clear that the legal action will be resisted.

“The instructions of the Minister are to oppose the challenge, and to do so as expeditiously as the court can allow.”

Adjourning proceedings until next week, Mr Justice McAlinden assured the parties: “I will clear whatever dates you agree, move other cases and get (another judge) to deal with them.”