Broadcaster and naturalist Chris Packham CBE is launching a legal challenge against the decision to go ahead with HS2.

The TV star, who has vehemently opposed the controversial railway project for years, has argued that it will have "severe negative impacts in a time of ecological and climate emergency".

Law firm Leigh Day has sent a Pre-Action Protocol letter on behalf of Mr Packham, arguing that the decision to give the go-ahead to HS2 was unlawful because it relied on the flawed Oakervee review process and did not take into account the full environmental costs of the project.

He said: "We live in a time of absolute crisis. Our future and that of the planet upon which we live and depend is critically threatened. Therefore, we look to our leaders not just for good, but for great governance.

"We ask for best informed decisions to be made in the terrifying face of a declared climate and environment emergency. Every important policy decision should now have the future of our environment at the forefront of its considerations.

"But in regard to the HS2 rail project I believe our government has failed. I believe the review central to the mandate to proceed was seriously flawed in its methods.

"I believe that essential submissions regarding environmental concerns were ignored by the review panel. As a consequence, the Oakervee review is compromised, incomplete and flawed and thus the decision to proceed based upon it is unlawful.

"Today some of us are making a last stand for nature and the environment and we will not go quietly into any good night.”

According to Mr Packham, the report of the Oakervee review failed to adequately provide a thorough assessment of the issues, including the environmental costs of construction and of climate change.

Since the initial environmental statement for HS2 Phase 1 in 2013, the Government has signed the Paris Agreement and committed to a policy of achieving net zero by 2050.

In his legal case Mr Packham argues that the Prime Minister’s decision relies on the mistaken understanding that the Oakervee report had taken carbon emission impacts into account, such as the facilitation of airport growth and expansion outside of London.

Tom Short, solicitor at law firm Leigh Day, said: “The government committed to base its decision of whether and how to proceed with HS2 on the output of a review that the public was assured would be rigorous and independent and would consider all the existing evidence and the full range of the costs of the project.

"Our client considers that the review has failed to meet those promised standards. He argues that the flawed process of the review means that environmental impacts relevant to the decision whether to proceed have not been properly assessed.

"In a time of unprecedented ecological catastrophe, he is clear that the law, and moral logic, require the government to think again.”

Chris is fundraising for his case at