Niamh Mahon
at the Court of Appeal

Geraldine O'Neill, whose brother Shane was killed on the A5 in 2008, is "absolutely delighted" with the result.

"This is a big day. Great for Tyrone," she says.

"We were hopeful, but we've been hopeful before and we've had our hopes dashed, so it's just fantastic day."

Patsy Kelly, a former SDLP councillor, says: "Get a move on and get it built."

"The best thing to see today is see two ministers from two different departments, two different parties working together.

"Just imagine what we could do in this country if everybody worked together."

Taoiseach (Irish Prime Minister) Micheál Martin has welcomed today’s decision, saying the Irish government has long supported the project.

"Road safety is a key concern, and too many lives have been lost in tragic circumstances along the A5 over the years," he says.

He adds that a funding commitment of €600m (£509m) to the A5 upgrade remains in place.

The total cost of the project is estimated to be in the region of £1.7bn.

Davy Wilson
in Bready, County Tyrone

At the Sollus Centre in Bready - one of the most recognisable roadside buildings on the stretch of the A5 that runs between Derry and Strabane - a group of crafters were hard at work on Tuesday morning as news of the judgment came through.

Florence Hall is among them. She says news that the scheme can go ahead is welcome.

"The road needs an upgrade, it needs more passing bays, needs modernised and updated. We don’t need a brand new road but it needs widened,” she told BBC News NI.

She said while there are problems with the road she has concerns about how people drive on it.

“Too much speed sometimes and not enough care,” she says.

Elizabeth Given too says the local A5 stretch needs upgraded.

But she also worries a new road will mean “more speed from drivers”.

“More speed can mean more human error.

“A lot of accidents are down to human error, maybe not down to the road itself. I hope a new road doesn’t mean more speed.”

John Campbell
BBC News NI economics and business editor

This decision is not just about the A5.

It is about the ability of Stormont to build important infrastructure - things like roads and railways which are essential to the economy.

The original High Court ruling found that Stormont’s 2022 climate law set a very high bar for the construction of new infrastructure.

To some observers, it looked like a climate veto on road building.

As well as the A5 being blocked, other projects were effectively paused.

The Court of Appeal has now decided that the bar was set too high.

This does not mean that Stormont ministers can ignore the Climate Act but it will give them confidence that other properly planned infrastructure will be able to proceed.

Niamh Mahon
at the Court of Appeal

Minister for Agriculture Andrew Muir says this is an important day.

"To be honest, I'm quite emotional about this because Liz and I worked together for this appeal because we believe that this project should proceed.

"This is an important judgment because it's clarifying that climate action and major infrastructure projects are not incompatible - they go together.

"And what we need to do as an executive is to move forward, to see this road delivered, and also to see climate action occurring in Northern Ireland. I'm committed to that. Liz is committed to that, and this has to be a team effort."

Niamh Mahon
at the Court of Appeal

Image source, PA Media

Infrastructure Minister Liz Kimmins is at court today.

"Today is a hugely positive day, and for me, today is about the families. I want to thank them for their unwavering support as we went through this process. It does not take away their grief," she says. "We know how important this essential road infrastructure scheme is for them."

She says she is "absolutely delighted" with the ruling.

Both her department and the Department of Agriculture worked together to ensure they made the "strongest, most robust" case to the Court of Appeal, she adds.

"We're delighted they took the time to carefully consider and reach the conclusion that they have today. So for me now, the top priority is let's get on with it, let's get this road built."

Niall McCracken

While reaction to the Court of Appeal's decision continues to filter in, here's a recap of how the case got there.

The 58-mile stretch of tarmac that traverses the west of Northern Ireland known as the A5, has rarely been out of the headlines in recent years.

The road is the Northern Ireland part of the major arterial route that connects the north-west of the island - Donegal and Londonderry - to Dublin, via towns including Strabane, Omagh and Aughnacloy

More than 50 people have died on the road since 2006.

Campaigners who want a new dual carriageway say the current road is not safe and claim its outdated design increases the risk of driving mistakes and accidents.

But others have raised opposition to the amount of land and farms that will be affected by a new road, as well as environment concerns around the construction of a carriageway.

Last year, a group of residents, landowners and farmers took a legal challenge to stop work on the project.

A judge found the project should not go ahead in its current form, saying the Department for Infrastructure's plans did not comply with climate change targets.

The department then took the case to the Court of Appeal and the ruling went in its favour.

Davy Wilson
in Ballymagorry, County Tyrone

David Connolly’s home sits right on the A5 on the outskirts of the village of Ballymagorry.

He has been keeping across proceedings in Belfast and says the go-ahead for the road upgrade is “great news”.

"It is a shocking road, way too dangerous and too many lives have been lost on it. The whole thing, the whole upgrade has taken way too long.

“Now I hope this judgment sees work get going on the upgrade as soon as possible.”

Niamh Mahon
at the Court of Appeal

Niall McKenna, from the campaign group Enough is Enough, says they are not celebrating.

"Our campaign was all about saving lives. It was certainly not to win court cases. But at the moment, I do feel a sense of pride."

Speaking outside court, he says: "I feel a sense of pride of our senior counsel, Stephen Toal, whose arguments were so accepted, particularly around the area of human rights."

"But I say it's not a time for celebration, and my most pride is for the people who stand behind me, the families of victims of the A5, almost 60, in the 20 years that this road was supposed to have been delivered, and it's too late for those people.

"Their loved ones are already gone, but they have campaigned tirelessly to make sure that no other families have to suffer the pain that they've went through. Thank you."

Niall McCracken
at the Court of Appeal

“The A5 Western Transport Corridor is a priority investment for the Northern Ireland Executive and will deliver several benefits including improving road safety and connectivity," says Lady Justice Keegan.

"Road safety is an obvious and pressing issue given the number of deaths that have occurred on this road, particularly of young people”

She says the A5 project was “larger than any road project ever undertaken in Northern Ireland” and “inevitably this issue intersects with the Climate Change Act".

She says the previous trial judge had “failed to factor in that the Department for Infrastructure and the executive were aware of the wider transport sector emission issues”.

She finds his ruling that the decision to proceed with the A5 road project braced the Climate Change Act “cannot stand”.

Catherine Morrison
BBC News Northern Ireland reporter

The Court of Appeal says there had been "no suggestion" the underlying legislation (the Climate Change Act) is unworkable by any parties.

They said they were satisfied that legal obligations cannot prevent a new road being built where it has been assessed to be - as far as possible - compliant with the new climate change rules.

Catherine Morrison
BBC News NI

Lady Chief Justice Keegan says the fundamental error the judge made was the failure to consider how the decision fitted within climate targets across Northern Ireland as a whole.

The Court of Appeal says the judge was wrong in his approach and the outcomes he reached in relation to the issues identified earlier, environmental impact assessment, human rights and climate change obligations.

Niall McCracken
at the Court of Appeal

The court has overturned a decision that blocked work commencing on one of Northern Ireland’s largest roads projects.

While the judgment is being delivered, here's a quick summary of the arguments over the A5 Western Transport Corridor project, to give it its full title.

• A plan for a new A5 dual carriageway was first proposed nearly 20 years ago, but it has been at the centre of a raging debate ever since
• Campaigners say a new, safer road is needed after a high number of fatal crashes along the route. More than 50 people have died on the A5 since 2006
• On the other side, people are worried about the impact of the project on farmland and the environment

Niall McCracken
at the Court of Appeal

Lady Justice Keegan says the A5 project was “larger than any road project undertaken in Northern Ireland” and “inevitably this issue intersects with the Climate Change Act".

“While the scheme will increase emissions it is a priority investment and should be proceeded with.”

Niall McCracken
at the Court of Appeal

Justice Keegan outlines how the trial judge did not find a substantive breach in human rights but more a procedural one.

Justice Keegan says the Court of Appeal found some “deficits” in the reasoning.

“Human rights issues were clearly taken into account in this case," she says.

She added there was “substantial evidence” from the Department for Infrastructure on the issue of the impact that this road would have on landowners and their human rights.

“Overall we find the argument based on human rights to be unconvincing and the judge went too far and made assumptions which he should not have made," she adds.

The Court of Appeal therefore reversed the judge's findings on the human rights issue.

This map gives a good visual overview of where the A5 is in Northern Ireland, its current route and the proposed new route.

Catherine Morrison
BBC News NI

Lady Chief Justice Dame Siobhan Keegan is delivering the judgment.

We aren't sure how long it will take but one of the first things she said was that it was "no overstatement" to say the litigation history of the A5 project was "long and tortuous".

Keegan is working her way through the four main grounds of this challenge.

Dealing with first one - the judge's quashing of the A5 project on grounds of EIA (Environmental Impact Assessment) obligations - the Court of Appeal has found the trial judge erred in his analysis of EIA compliance.

The Court of Appeal has found in favour of the appellants, the Department for Infrastructure, on EIA grounds and has reversed the decision of the trial judge on this aspect of the challenge.

The court's decision on the future of one of Northern Ireland’s largest road projects is due later.

Proposals to build a new dual A5 dual carriageway between Londonderry and Aughnacloy go back almost 20 years, but have been beset by funding and legal issues.

The improvement scheme was given the go-ahead by Stormont ministers in October 2024.

But last year, a court ruled the Department for Infrastructure's plans for the road did not comply with climate change targets.

Today the Court of Appeal in Belfast will decide on whether to uphold or quash that High Court judgment.

We are expecting the judgment on the future of the long-delayed A5 road project today.

We will hear whether the Court of Appeal will uphold a 2025 High Court decision that the plans breached Northern Ireland's climate change targets.

The Department for Infrastructure is challenging that decision.

Stay with us and we will bring you the latest from court and all the background to the case.