M4 relief road proposals ‘should stay in the past’

Welsh political leaders came to blows over long-discussed proposals for a relief road during a hustings hosted by WalesOnline

18:44, 09 Apr 2026Updated 21:22, 09 Apr 2026

Congestion around the Brynglas Tunnels is a common sight for drivers on the M4(Image: John Myers)

Environmentalists and business leaders have clashed over the renewed hope of building a new road to reduce traffic congestion around the Brynglas Tunnels on the M4 in Newport.

Having been on and off the political agenda for decades, the topic has re-emerged ahead of next month's Senedd election. Environmentalists said the proposals should stay in the past "where they belong", while those in the business sector have called the current congestion problems "a major drag" on Welsh businesses.

When the six main parties were asked during the WalesOnline leaders hustings[1] earlier this week whether they would build one, three want a road - of some description - and three maintain no road should be built.

Labour[2], the Liberal Democrats[3] and the Green Party all oppose a road. Reform UK and the Conservatives want a relief road - but Reform UK say it could be a toll road, something the Tories have ruled out.

For the biggest stories in Wales first sign up to our daily newsletter here[4].

Plaid Cymru[5] said it thinks something has to be done and believes a new road is part of the solution, saying it will build the case for it. However, all their manifesto says is they are clear about "the pressing need to address congestion on the M4 around Newport".

In 2019, Mark Drakeford's Labour government scrapped plans to build the six-lane road citing high costs, estimated at the time to be GBP1.6bn, and environmental factors. The Welsh Government subsequently said the cancelled project had cost taxpayers GBP114m over six years, including the GBP44m spent on a public inquiry.

The decision was met with relief on some sides of the political sphere, and despair on others.

For

Speaking after this latest discussion between party leaders, the Head of the Federation of Small Business (FSB) in Wales, Joshua Miles, said infrastructure investment is vital in order to help Welsh businesses.

He added that it was encouraging to see politicians engaging with the issue of a relief road again.

He said: "FSB Wales is clear that we need a step change in infrastructure investment as part of a new deal for businesses in Wales. That includes key pinch points across Wales such as the Britannia Bridge on Ynys Mon, rail enhancements in northeast Wales and reducing congestion on the M4[6] in and around Port Talbot[7].

"The Brynglas Tunnels have long been a major drag on growth for smaller businesses, and it's encouraging to see the political parties engaging with the problem ahead of the election. The next Welsh Government[8] needs to take a thorough look at the options including both road and rail, with a view to making real progress on the issue."

In their Senedd manifesto, the Confederation of British Industry (CBI), also called for the next Welsh Government to invest in "critical infrastructure", including the M4 relief road.

Director of CBI Wales Russell Greenslade said the case for an M4 relief road remains pressing due to congestion on the existing and ageing M4 remaining a major concern for businesses.

He continued: "From a transportation and connectivity point of view, the more we have, the better, and an M4 Relief Road would be an example of that.

It is not just the M4, but also the A55 in North Wales, which, to quote some of our members, can often be like a car park.

"There is a lot of growth happening in Newport with the compound semiconductor cluster. If we are going to attract more people to work there, then the transportation network needs to be improved."

Against

However, the project being raised again has also been heavily criticised for enironmental reasons. With the previously touted 14 mile stretch of motorway designed to run between Magor and Castleton it would encroach onto the protected Gwent Levels.

The Gwent Wildlife Trust has repeatedly campaigned against plans to build a road.

When Mr Drakeford cancelled it in 2019, the organisation said the decision to scrap "the UK's most ecologically damaging motorway scheme" was great news.

Speaking after the WalesOnline hustings, a spokesperson for Friends of the Earth Cymru said such plans would distract from the much-need public transport plans and not properly address congestion.

They said: "New roads are expensive and time-consuming projects which instead of addressing congestion lead to more cars on the road, more carbon emissions, and more air pollution - and distract from the much-needed public transport improvements which would help people travel safely and affordably.

"M4 road proposals around Newport[9] should stay where they belong - in the past and long discredited."

You can watch the WalesOnline hustings in full on our YouTube page and Facebook[10] page.

References

1. ^ during the WalesOnline leaders hustings (www.walesonline.co.uk)
2. ^ Labour (www.walesonline.co.uk)
3. ^ Liberal Democrats (www.walesonline.co.uk)
4. ^ sign up to our daily newsletter here (www.walesonline.co.uk)
5. ^ Plaid Cymru (www.walesonline.co.uk)
6. ^ the M4 (www.walesonline.co.uk)
7. ^ Port Talbot (www.walesonline.co.uk)
8. ^ Welsh Government (www.walesonline.co.uk)
9. ^ Newport (www.walesonline.co.uk)
10. ^ Facebook (www.walesonline.co.uk)