The UK government's advisory body on tackling climate change on Tuesday voiced concern at the slow pace of the transition to clean energy, warning time was running out to meet its goals.
The independent Climate Change Committee (CCC) said it was "markedly less" confident than a year ago that the country could meet its goals to cut carbon use by 2030.
Growing sales of new electric cars and new renewable energy projects provided "glimmers" of hope, it said but added that "the scale up of action overall is worryingly slow".
The CCC said ministers were over-reliant on technology that had not been rolled out at scale, rather than encouraging the public to reduce high-carbon activities.
CCC chairman John Gummer said "early action" was cheaper in the long run and allowed looming environmental challenges to be met more easily.
"Yet, even in these times of extraordinary fossil fuel prices, Government has been too slow to embrace cleaner, cheaper alternatives and too keen to support new production of coal, oil and gas," he added.
Gummer spoke of a "worrying hesitancy by ministers to lead the country to the next stage" needed to arrive at the country's net zero commitments and urged them to commit to bolder delivery.
"This is a period when pace must be prioritised over perfection," he said.
- Undermined -
At the UN climate change conference in Glasgow in 2021, the UK pledged to cut greenhouse gas emissions by 68 percent by 2030, compared with 1990 levels.
But emissions had so far only fallen 46 percent, the CCC pointed out.
"In only seven years, the recent rate of annual emissions reduction outside the electricity supply sector must therefore quadruple," it added.
"Time is now very short to achieve this change of pace."
The CCC said the UK, which has had three prime ministers since last July, including the short-lived Liz Truss, who lifted a ban on fracking, had sent "confusing signals" on its climate ambitions, undermining its COP26 commitments.
Under Prime Minister Rishi Sunak, approval has been given for a new coal mine in northwest England while the government has signalled support for new North Sea oil and gas exploration
The panel said the government has "no clear policy" to deliver its aims of decarbonised steel production, and upgrading the electricity grid to include renewable infrastructure, particularly onshore wind, is caught up in planning restrictions.
The CCC urged more tree-planting and use of domestic heat pumps, and a moratorium on airport expansion.
The UK has pledged to be carbon-neutral by 2050, and wants to cut its reliance on imported fossil fuels, to stop its exposure to volatile price fluctuations such as those seen since Russia's invasion of Ukraine last year.
At the end of March this year, the CCC criticised the UK government's "lack of urgency" about adapting to higher temperatures, after record-breaking heat and recurrent flooding last year.