Labour remains committed to invest £28 billion a year in green projects as its “level of ambition”, the shadow business secretary has said.

Jonathan Reynolds conceded the investment may not be seen until the latter part of the next parliament and that “circumstances do change”.

Under its green prosperity plan announced in 2021, Labour had promised to invest £28 billion a year until 2030 in green projects if it came to power.

However, party leader Sir Keir Starmer previously hinted he could scale down the investment given the financial picture he would inherit if he becomes prime minister while the party was forced to deny allegations it had axed the pledge last week.

Asked whether Labour would spend £28 billion a year or not if in power, Mr Reynolds told Sky News on Sunday: “How much you can spend is determined by the health of the economy, which is clearly in a challenging position, and our own fiscal rules, which want to see debt fall by the end of a parliament.

I think we’ve got some very clear positions. I think circumstances do change, and particularly the health of the public finances, the cost of borrowing, that did change remarkably in the last few years

“So, we’re still committed to that level of ambition but we’re clear it is the fiscal rules that determine whether you can do that, and that is not because we’re limiting our ambition in that space – it’s a recognition if you don’t have that discipline, you end up with the kind of disaster we saw with Liz Truss where you’re spending more money, but it’s only that interest, rather than the investments, that you want to make.”

Mr Reynolds said news earlier this week of up to 2,500 job losses at the Port Talbot steelworks showed the current Government “still spend a lot of money, but they’ll do it to make thousands of people redundant”, and that the next government will have to cope with “the worst inheritance ever”.

He labelled Chancellor Jeremy Hunt’s discussion of further tax cuts in the coming months as “a scorched earth policy”.

Asked on Sunday with Laura Kuenssberg whether Sir Keir was prone to showing uncertainty on his party’s policies, Mr Reynolds said: “I think we’ve got some very clear positions. I think circumstances do change, and particularly the health of the public finances, the cost of borrowing, that did change remarkably in the last few years.

“You’ve got no choice in opposition but to reflect on that and therefore put your programme forward, because, again, people don’t want promises that won’t be delivered.”

Aside from policies, he said voters should consider Sir Keir’s transformation of the Labour Party in recent years as a reason to put their confidence on him as a future prime minister.

He said: “Look at where the Labour Party was in 2019 – I mean, literally, in an absolutely terrible state.

“I don’t think most people believed one party leader in one term of parliament could bring Labour back from that to being competitive at the next election.

“Now he has done that and the courage, the resolve, the resilience, he’s had to show to do that tells you about the kind of prime minister he could be and would be if he’s given that choice.”