Dozens of environmental groups are calling on the Government to launch a public inquiry into plans to open a coal mine in Cumbria.

Some 80 organisations, including Greenpeace and The Wildlife Trusts, have signed a letter to the Prime Minister in which they described the “mystifying” disbelief that the Government had not intervened over the approval of plans for the mine in Whitehaven.

It comes after climate scientist James Hansen warned Boris Johnson faced “humiliation” over the plans, and that failure to stop the mine from going ahead would be in “contemptuous disregard” for the future of young people and nature.

The new facility, which will be used to extract coking coal for steel production, has been granted planning permission by Cumbria County Council.

In a letter coordinated by Greenpeace and countryside charity CPRE, the environmental groups said the UK is due to play host to the international Cop26 climate summit in Glasgow in November.

“Given that our credibility, as host of the largest global climate talks since the signing of the Paris Agreement is at stake, it is mystifying that the government has decided not to intervene in the approval of the UK’s first deep coal mine in 30 years,” they said.

While they acknowledged new jobs needed to be created, the signatories said investment in green energy would “provide significantly more than the 500 jobs promised by the new mine”.

They urged Communities Secretary Robert Jenrick to refer the matter to a public inquiry.

It follows another letter to the Prime Minister by former Nasa scientist Mr Hansen, in which he said Mr Johnson had “a chance to change the course of our climate trajectory, earning the UK and yourself historic accolades”.

He added: “Or you can stick with business-almost-as-usual and be vilified in the streets of Glasgow, London, and around the world.

“It would be easy to achieve this latter ignominy and humiliation.

“Just continue with the plan to open a new coal mine in Cumbria and continue to invest funds of the British public in fossil fuel projects overseas, in contemptuous disregard of the future of young people and nature.”

Campaigners, including climate activist Greta Thunberg, have criticised the go-ahead for the coal mine, warning it undermines the Government’s claims it is committed to cutting emissions to net-zero by 2050.

Coal creates carbon dioxide emissions when burned for energy and also when used for steel making and other industrial processes such as cement.

Responding to that decision, Conservative former environment secretary Lord Deben, who chairs the independent Climate Change Committee, said it gave a “negative impression of the UK’s climate priorities”.

He said: “The mine is projected to increase UK emissions by 0.4Mt (megatonnes) of CO2e (carbon dioxide equivalent) per year.

“This is greater than the level of annual emissions we have projected from all open UK coal mines to 2050.”

The Government said in January that it would not call in the plans for an inquiry.

A No 10 spokesman said the UK “continues to lead the fight against climate change” and had cut emissions “more than any major economy so far”.

The spokesman added: “We have already committed to ending the use of coal for electricity by 2025 and ending direct government support for the fossil fuel energy sector overseas.

“On top of significant government investment, we will also bring forward a strategy this year to decarbonise industries like steel, and the manufacturing processes they rely on.”