A landmark bill that would make the UK’s climate and environment targets legally binding seems doomed after government whips ordered Labour MPs to oppose it following a breakdown in negotiations.

Supporters of the climate and nature bill, introduced by the Liberal Democrat MP Roz Savage, say Labour insisted on the removal of clauses that would require the UK to meet the targets it agreed to at Cop and other international summits.

Although it is a private member’s bill, more than 80 Labour MPs, including several ministers, had publicly signed up to support it.