This is a time for climate leadership, not cowardice - Lorna Slater

Minister for Green Skills, Circular Economy and Biodiversity, Lorna Slater

It had already been the subject of months of leaks and briefings, with Shadow Cabinet members refusing to commit and senior Labour figures telling journalists it was an “albatross” around their necks.

Coming on the same day as climate experts revealed that average global temperatures have breached the critical 1.5C safe threshold for the first time, Starmer’s timing could hardly have been worse.

Our climate isn’t a political prop. It is essential to the future of our planet and all governments need to take it seriously.

Rishi Sunak's attacks on Keir Starmer over changes of policy may hit home with voters (Picture: Stefan Rousseau/WPA pool/Getty Images)

When he initially made the pledge I was optimistic. It was good to hear a Leader of the Opposition who recognised the scale of the crisis and the urgent need to decarbonise our economy and invest in green jobs.

It suggested a level of urgency and ambition that has been lacking in Downing Street. I hoped we could work positively and constructively with him if he became PM, but his U-turn hugely undermines that.

From fixing our broken energy market to changing the way we heat our homes, getting cars off our road and reducing our reliance on oil and gas, there is no shortage of work to be done. This is essential for our climate and will help build a vibrant and green economy that is fit for the future.

But it won’t happen by itself. It needs investment and, most of all, it needs political will. It needs governments and leaders who are willing to step up to the challenge.

That is what we have focused on in Scotland and what we will never shy away from. While Starmer was going back on his word, our Parliament was debating a Budget that included a record £4.7 billion of climate investment. We are delivering this within the tight confines of devolution and cuts imposed by Westminster.

We choices we are making are having an impact: creating thousands of new green jobs in the renewables sector, delivering a record rate of clean heat system installations and the most ambitious ever programme to ensure people have warmer, greener homes with lower energy bills.

It would be easy to make this about party politics, but it’s much bigger than that.

There are a lot of Labour MPs and MSPs who I have worked with and who I respect and who know how central our climate has to be to everything we do. I know that they will have been just as dismayed as I am.

I hope they stand up to their leader and ensure that if he makes it to Downing Street he lives up his promises and takes the climate action that is so crucial.

Lorna Slater, Minister for Green Skills, Circular Economy and Biodiversity