Labour has strongly denied reports that Sir Keir Starmer could water down the party’s pledge to spend £28 billion-a-year on green initiatives.

Both the BBC and the Telegraph reported that the plan could be scaled back again as Labour instead focuses on meeting the party’s fiscal rules.

Labour had originally promised in 2021 to invest £28 billion-a-year until 2030 in green projects if it came to power. But in June shadow chancellor Rachel Reeves said the figure would instead be a target to work towards in the second half of a first parliament.

The BBC said that a senior source in Sir Keir Starmer’s office suggested the £28 billion figure may not be reached at all due to the current state of the public finances.

A source also told the Telegraph that fulfilling Labour’s fiscal rules was more important than meeting that pledge, with the paper reporting that aides to Sir Keir have asked Ms Reeves to scale back the fund.

A Labour Party spokesperson said it was “categorically untrue” that Sir Keir had asked for the plans to be “watered down”.

The spokesperson said all policies would be subject to Labour’s fiscal rules but the position on the green prosperity plan remained “unchanged”.

The party’s rules include paying for day-to-day expenditure through tax receipts and getting debt down as a share of the economy.

“Labour will ramp up investment in jobs and energy independence through our green prosperity plan to a total of £28 billion a year as planned in the second half of the parliament,” the spokesperson said.

The Tories have latched onto the policy to attack Labour’s fiscal credibility, attacking the idea of the extra borrowing needed to fund the pledge.

The reports had prompted concern from climate campaigners.

Hannah Martin, co-director of the Green New Deal Rising campaign group, warned on Saturday any such move would be a “disaster”.

It comes after Jeremy Hunt’s autumn statement offered significant tax cuts, but pencilled in steep curbs in public spending beyond the next general election.

Sir Keir has already acknowledged that his party will face “tough choices” if it wins the next general election.