One of the UK’s largest trade unions will not endorse Labour's manifesto in protest at the party's policies on workers' rights and oil and gas.

Unite has refused to give its backing to the final version of the document, which was signed off on at the party’s closed-doors Clause V meeting on Friday.

The union, which donated £3 million to Labour’s campaign in 2019, is one of the biggest financial backers of the party. 

Unite general secretary Sharon Graham, cancelled planned talks with reporters after a secretive gathering in London where senior figures in the party signed off on the manifesto.

Sources close to the union boss said the failure to ban fire and rehire practices, zero-hours contracts and block oil and gas licences meant she could not endorse it.

READ MORE: Unite Union boss Sharon Graham: “Labour have to be much bolder,”

A Labour spokesperson said: “Today’s meeting has endorsed Labour’s manifesto. On July 4, the British people will have the chance to vote for change – to stop the chaos, turn the page and start to rebuild our country.”

Shadow foreign secretary David Lammy said he was “surprised to hear” that Unite had declined to back the policy document because there had been no votes against the proposals at the meeting.

“I’m surprised to hear that, because genuinely, hand on heart, I’d say that wasn’t the mood of the room,” he told Times Radio.

The SNP said the fallout was “damning.”

Depute leader Keith Brown said: “It’s damning that a major trade union has refused to endorse the Labour Party manifesto because of the threat to thousands of jobs in Scotland’s energy sector – and the watering down of workers’ rights proposals.

“It’s clear that only the SNP can be trusted to stand up for Scotland. A vote for the SNP on July 4 is a vote to protect Scottish jobs and put Scotland’s interests first.”

The manifesto will be based on the party’s five missions for government announced last year on the economy, the NHS, energy, education and planning reform.

Labour has watered down some of its previous commitments, such as a pledge to spend £28 billion a year on green energy projects, as it seeks to reassure voters that it would manage the economy responsibly in government.

Party policies now include the creation of GB Energy, a publicly owned sustainable power company, 40,000 more NHS appointments a week and the recruitment of 6,500 new teachers to plug gaps in the workforce.

Earlier on Friday, Sir Keir also confirmed that recognition of Palestinian statehood as part of any Middle East peace process would be included in the document.

The Labour leader suggested that such a move should not be blocked by a neighbouring country, saying it was an “inalienable right” of Palestinians and not in “the gift of Israel”.

The manifesto is expected to be launched next Thursday.