Investment in wind and solar power has crashed since the Government slashed the help available, new figures show – while much of the world powers ahead.

The dramatic slump – a 56 per cent fall in a single year – sparked an accusation that the Government is failing in its environmental strategy, despite its “green veneer”.

Ministers were also warned they are in danger of missing their own legally binding carbon reduction targets and that Brexit will “make the problem even worse”.

The 56 per cent plunge in investment in renewable energy in 2017 marks the second successive year that financing has fallen in the UK.

It follows a ban on subsidies for onshore wind farms and huge cuts to help for solar power, both imposed by David Cameron’s government.

Meanwhile, the last Budget ruled out any fresh support for renewables before 2025 at the earliest – despite investors’ pleas that they need a long-term policy framework in order to act.

The decline in the UK was the largest in the world, while the likes of China (up 24 per cent), Spain (up 36 per cent), Canada (up 45 per cent) and the Netherlands (up 30 per cent) enjoyed strong growth.

Caroline Lucas, the co-leader of the Green Party, said: “Behind the Government's green veneer we see continued failure on green energy.

“Under the Prime Minister's watch, investment in clean technology has slumped, because of government policy changes. Make no mistake, these new statistics are damning.”

And Mary Creagh, the Labour chairwoman of the Commons environmental audit committee, said: “This is the second year in a row that renewable energy investment in the UK has nose-dived.

“Current rates of investment simply won’t deliver enough renewable energy to meet our legally binding carbon reduction targets. Losing European Investment Bank funding if we leave the EU could make the problem even worse.”

The figures were revealed to Ms Creagh’s committee by Bloomberg New Energy Finance, an organisation which compiles a database of projects and deals from across the world.

It noted that the UK investment decline - to $10.3bn – flowed from “changes in policy support”, which included a 65 per cent cut to subsidies to householders installing rooftop solar panels, in late 2015.

Minister said their priority was to “ensure energy bills for hardworking families and businesses are kept as low as possible”, rather than boost support for low carbon technologies.

Last November, the Chancellor confirmed there would be no fresh funds for new renewable energy projects levied through electricity bills until at least 2025.