Campaign group Friends of the Earth has filed papers in the High Court challenging the Government's Net Zero Strategy (NZS) and its Heat and Building Strategy over "lacklustre" commitments to tackling climate change, making the policy the subject of two separate legal challenges.
The group says the NZS, published in October last year, does not comply with requirements under the Climate Change Act 2008.
It also contends that the Heat and Building Strategy did not consider the impact on legally protected groups under the Equality Act 2010.
The environmental non-profit's challenge came on the same day (13 January) as ClientEarth's legal challenge of the NZS, which argues the Government's policies are "inadequate" for meeting carbon budgets and are not compatible with human rights law.
In its challenge, Friends of the Earth claims the pathways to reach net zero in the NZS are theoretical, because they are not supported by government policy which shows how they can be fulfilled. This means that the NZS is not lawful and does not allow parliament and members of the public to hold the Government accountable for any failures, the group said.
It also claims that the Government failed to consider the impact of its Heat and Buildings Strategy, published at the same time as the NZS, on protected groups.
The group said factors such as age, sex, race, and disability can make people more vulnerable to climate impacts.
The environmental group raised concerns that people in these groups can be unfairly and disproportionately impacted by a badly planned transition to low carbon living. "Yet the government has not identified and considered their specific needs as required by the Equality Act 2010," it said.
Part of the group's argument centres around fuel poverty, which it says people of colour are twice as likely to experience compared to white people. In addition, areas identified by the Government as having a high number of residents with disabilities or other health needs are more likely to be rated in the worst category for fuel poverty, the group said.
The Government did not consider these factors, according to the group.
Rowan Smith, a solicitor at Leigh Day, said that under the Climate Change Act 2008, "the Secretary of State has a legal obligation to set out how the UK will actually meet carbon reduction targets".
He added: "Friends of the Earth considers that the Net Zero Strategy lacks the vital information to give effect to that duty, and so any conclusion, that targets will be achieved on the basis of the policies put forward, is unlawful.
"Friends of the Earth is concerned that this places future generations at a particular disadvantage, because current mistakes are harder to rectify the closer we get to 2050. That is why this legal challenge is so important."
Katie de Kauwe, lawyer at Friends of the Earth, said: "A rapid and fair transition to a safer future requires a plan that shows how much greenhouse gas reduction the chosen policies will achieve, and by when. That the plan for achieving net zero is published without this information in it is very worrying, and we believe is unlawful."
She added: "We know that those who do least to cause climate breakdown are too often the hardest hit. Climate action must be based on reversing these inequalities, by designing the transition with the most vulnerable in mind. Not even considering the implications of the Heat and Building Strategy on groups such as older and disabled people, and people of colour and ethnic minorities is quite shocking, given these groups are disproportionately impacted by fuel poverty, for example."