NEWPORT council is set to give qualified support to the M4 Relief Road amid environmental concerns and worries it could bypass the city, a council document shows.

The authority says it backs the Welsh Government’s preferred three-lane motorway route over the Gwent Levels in a proposed response to the M4 consultation, but said there wasn’t enough detail on air quality and other issues.

The document says the road would have a significant impact on Newport’s ecology and could risk severing the city from the coastline.

It says an alternative route would also provide additional capacity with less impact on the environment.

The Labour cabinet member for infrastructure John Richards has yet to sign off on the response which has been sent out to councillors for comment, although he said he had no objection to it.

In the report Cllr Richards says: “I have concerns relating to the prospect of another major road by-passing the city which may adversely affect our economic and regeneration aspirations.

“I also have concerns that sustainable public transport is not being considered together with the proposed route for a new motorway.”

The report says Newport council supports the Welsh Government’s proposed ‘black’ route – a three lane motorway over the Gwent Levels – to resolve the M4 congestion issues at the earliest opportunity.

But it said a minimum of three junctions in Newport – east, west and central – would be needed to ensure the city is not bypassed “to the detriment of its economic growth and regeneration”.

It also said that the “the effect of the proposals on the surrounding highway network in terms of capacity, safety, community severance, noise and air quality cannot be determined at this time”.

The black route would have a “significant impact of the ecology of Newport”, the report says, affecting protected species and sites of international, European, National and regional importance.

Environmental assessments must be “robust”, the council says, with a “mosaic of habitats” existing within the site of special scientific interest.

The route would also have a “significant impact on the landscape”, saying mitigation measures would need to be agreed early on.

The new M4 could sever the city from the coast line, and communities on the Gwent Levels from key services and facilities, unless the impact on the public rights of way network is not well managed, the response says.

An alternative ‘purple’ route would meet the goal of providing adequate additional road capacity on a convenient route with less of effect on Newport docks, the response says.

The purple route - which would still be a three-way motorway but would take a more northerly route, crossing the Newport north dock - would have less environmental impact than the black route, says the document.

However the effect on existing residential areas, including Duffryn, and other business and industrial zones could be significant, while there would be a more direct effect on the population of Newport bringing the road closer to them.

A “do-minimum scenario” would do nothing to address identified problems, while an alternative ‘red route’ two-lane scheme would do little to resolve the issues, the response argued.