NEWS the planned M4 relief road has been pushed back by two years and will cost £136 million more than expected has been slammed by one of the most vehement objectors to the plan.

Earlier this week the Welsh Government was announced the new stretch of motorway may not be complete until 2023, two years later than planned, and its predicted costs had increased by about 10 per cent to 1.3 billion after a number of concessions were made to the organisation running Newport Docks.

But the Gwent Wildlife Trust, which has repeatedly objected to the proposal over the potential damage on the Gwent Levels, has slammed the news.

Chief executive Ian Rappel said: “As the Welsh Government’s public inquiry into the proposed new M4 is ongoing, we are disappointed that the minister Ken Skates has been making statements about the motorway plans before the inquiry has concluded and the inspector’s recommendations have been made.

"Welsh Government’s latest announcement is indicative of the spiralling costs to the taxpayer, as a result of this fallacy."

He added: "Their suggested new plans change nothing and Gwent Wildlife Trust remain vehemently opposed to a motorway being built across Wales’ equivalent of the Amazon rainforest.

“The proposed new M4 is massively damaging, totally unsustainable and uneconomical for both people and wildlife and its route will destroy an irreplaceable and precious area of the Gwent Levels forever."

If the Welsh Government's preferred 'black route' goes ahead, the motorway will cut straight through the docks. And, following negotiation with the Association of British Ports, which owns the docs, the Welsh Government announced a series of new measures this week, including massive new bridge, which will be taller than the second Severn crossing.

The next cheapest alternative would reportedly cost £100 million more.

A public inquiry into the plans began earlier this year and will resume at the end of January.

The Welsh Conservatives have previously said they are supportive of the black route, so it is likely to be passed if put to a vote in the Assembly.