Green MP Caroline Lucas has criticised Labour for ditching a pledge to spend £28 billion a year on green projects.

Labour leader Sir Keir Starmer announced last week that the figure would be drastically scaled back if his party wins the next election, but insisted the ambitions behind his party’s green prosperity plan remain the same.

One casualty of the U-turn is thought to be Labour’s plan to insulate homes, with only five million expected to be completed over five years rather than 19 million as initially promised.

Speaking to Victoria Derbyshire on the BBC’s Newsnight programme, the MP for Brighton Pavilion said: “What they [Labour] have done is U-turned on a whole set of commitments that they had up until just a few days ago.

“The bottom line here is we know the climate emergency is getting worse. It doesn’t just wait until Labour’s fiscal rules find it convenient for the investment to happen.

“I don’t think I would like to be a Labour MP looking into the eyes of my kids or grandkids saying ‘Really sorry I couldn’t pass on a liveable planet to you, but it actually wasn’t convenient for our fiscal rules.’

“There are such things as existential threats - that is what we face right now and I think nobody can really listen to Labour now and have confidence that they are going to deliver on what they’ve just said.”

Labour’s announcement came as the EU’s climate service announced that global warming had exceeded 1.5C across an entire year for the first time.

Sian Berry, who will stand as the Green candidate in Brighton Pavilion at the next general election, also condemned the move and said it was “the wrong decision for the climate, for the economy and for good quality jobs”.

She said: “The security of our planet and the health of the economy we will build for future generations is dependent on investing now to support new green industries and create millions of new jobs cutting the energy we consume at home and in businesses.

“That all requires large-scale government support, but with Keir Starmer’s announcement, it is clearer than ever that the next government will need Green MPs pushing for the deep investment people in Brighton and across the country really need.

“On the day we found out that the world has exceeded 1.5 degrees of warning for a whole year and when young people are crying out for even more investment in a Green New Deal, delivering less than ever is not ‘pragmatic’ from Labour - it’s a collision course with reality.”

The Argus: Sian Berry, the Green candidate for Brighton PavilionSian Berry, the Green candidate for Brighton Pavilion (Image: The Argus/Andrew Gardner)

Shadow Chancellor Rachel Reeves defended the U-turn on BBC Breakfast and said: “I’ll make no apologies for ensuring that our plan is fully costed, fully funded and deliverable within the inheritance we’re going to get.

“It is going to be a bleak inheritance after the damage the Conservatives have done to our economy.

“In the almost three years that I’ve been shadow chancellor, I think people have heard loud and clear from me that fiscal responsibility, economic responsibility, are the most important things for me because it is absolutely essential that the public finances are managed well.

“When economic circumstances change, your plans have to change as well.”