In a scathing annual progress report it said the committee's confidence in government being able to deliver promised emissions reductions from 2030 onwards was now "markedly less" than it was a year ago.

The report states: "A key opportunity to push a faster pace of progress has been missed.

"Time is now very short to achieve this change of pace.

"Glimmers of the net zero transition can be seen in growing sales of new electric cars and the continued deployment of renewable (power) capacity, but the scale up of action overall is worryingly slow."

A lack of progress on decarbonising heat in homes with technology like heat pumps, too much reliance on untested technology like carbon capture, and insufficient tree planting are among the policy areas singled out for criticism.

The UK, the committee said, is also sending "confusing signals" to the international community by supporting new oil and gas extraction and approving a new coal mine in Cumbria.

Committee chairman Lord Deben said: "We've slipped behind. The government has lost the leadership role it did have and carried through in the Glasgow COP26 summit.

"There's no doubt that Britain was leading the world… since then we've done a number of things which have run counter to that.

"We are still dithering about onshore wind, we haven't got the (electricity) grid even on its way to being right.

"We are still building homes that are not fit for the future. Right across the political spectrum, there is an unwillingness to lead.

"I'm sad that this, my last progress report, is not a report that suggests satisfactory progress.

"Everything we hold most dear is threatened by climate change… we can't let these chances go… because they won't come again and our children and grandchildren will ask us how it was that we let them down."

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Green Party MP for Brighton Pavilion, Caroline Lucas, said: "This report could hardly be more damning.

"We're going backwards more than we are forwards.

"This government's dangerous dither and delay has driven a coach and horses through the UK's previous reputation as a global climate leader."

Defending the government's record, and in particular its decision to encourage new oil and gas drilling in the North Sea, energy minister Graham Stuart said: "About 76% of the energy of the most decarbonized major economy in the world, us, comes from fossil fuels today.

"There is no button I can press that turns that off tomorrow.

"And as we will be dependent on oil and gas for decades to come, even as we move to net zero, it makes sense that we should produce it here."