Image caption TV naturalist and Springwatch presenter Chris Packham is launching a new legal challenge to HS2

TV naturalist Chris Packham has launched a legal challenge to HS2 high-speed rail link.

The Springwatch presenter said the government's approval of the controversial project fails to take carbon emissions targets into account.

Mr Packham said: "In regard to the HS2 rail project I believe our government has failed."

The Department for Transport (DfT) said it was considering the challenge and would respond "in due course".

Mr Packham said that the Oakervee review into the project's spiralling costs and delays was "compromised, incomplete and flawed".

The review strongly advised against cancelling HS2, saying it would benefit the transport system and there was no "shovel-ready" alternative upgrade for the existing railways. It did however recommend tighter controls on costs and better management.

Prime Minister Boris Johnson approved the decision to build the rail link in February, on the recommendation of the review.

HS2 is set to link London, Birmingham, Manchester and Leeds and it is hoped it will reduce passenger overcrowding and help rebalance the UK's economy.

Image caption Once built, London to Birmingham travel times will be cut from one hour, 21 minutes to 52 minutes, according to the Department for Transport

Leigh Day, Mr Packham's solicitors, sent a letter to the prime minister challenging the decision to go ahead with HS2.

The letter points out that the Oakervee report failed to take into account the full impact of HS2's potential carbon emissions impact. The initial environmental assessment for the project was published in 2013, before the government signed up to achieving "net zero" carbon emissions by 2050.

Tom Short, a solicitor at Leigh Day, said that the "environmental impacts relevant to the decision whether to proceed have not been properly assessed".

'Last stand for nature'

Mr Packham also argues that construction of the rail link would damage or destroy almost 700 wildlife sites, including about 100 ancient woodlands. Mr Packham added: "Today some of us are making a last stand for nature and the environment and we will not go quietly into any good night."

HS2 says that only 62 ancient woodlands would be affected, and that most would remain intact.

In response to the broadcaster's crowdfunded campaign, the DfT said: "We understand campaigners' concerns, and have tasked HS2 Ltd to deliver one of the UK's most environmentally responsible infrastructure projects.

"When finished, HS2 will play a key part in our efforts to tackle climate change, reducing carbon emissions by providing an alternative to domestic flights and cutting congestion on our roads."

The legal challenge follows a Court of Appeal ruling against the construction of a third runway at Heathrow Airport.

Judges found that the government's decision to allow the expansion was unlawful because it did not take climate commitments into account.