Campaigners against the UK’s controversial drug pricing deal with Donald Trump are threatening the government with legal action unless it scraps a key element of the plan.

They claim that a change to how drug treatments are approved for use by the NHS , which could lead to it paying even higher prices for them, amounts to an “unlawful power grab”.

The plan could let the health secretary override the independent judgment by the National Institute for Health and Care Excellence (Nice) as to how much the NHS should pay for certain medicines.