Green groups reacted with dismay as a politician branded a “climate dinosaur” who backs new fossil fuel extraction was named as the UK's energy secretary.

Jacob Rees-Mogg was moved to the top job at the Department for Business, Energy and Industrial Strategy (BEIS) by new Prime Minister Liz Truss, replacing Kwasi Kwarteng who is promoted to chancellor of the exchequer – the UK’s finance minister.

Rees-Mogg, previously the UK’s Brexit minister, is on the right of the ruling Conservative Party and a target for regular criticism from political opponents for his hardline opinions on a wide range of issues – as well as a famously eccentric persona more reminiscent of the 19th century than the 21st that has seen him lounging horizontally in the House of Commons during debates.

His pronouncements on climate and energy include that he would like his voters to have cheap power “rather more than I would like them to have windmills” and calls to extract “every last drop” of fossil resources from the North Sea.

The appointment of such a divisive figure to lead UK energy policy will inevitably fuel fears that Britain will move away from the focus on meeting net zero commitments that – for all the faults that ended his Premiership – was championed by Truss’s predecessor Boris Johnson and instead embrace renewed North Sea fossil activity and fracking.

Environmental group Friends of the Earth said Rees-Mogg’s appointment was “deeply worrying for anyone concerned about the deepening climate emergency, solving the cost-of-living crisis and keeping our fuel bills down for good.

“We need a forward-looking, modern energy strategy based on better home insulation and unleashing the full potential of the UK’s homegrown renewables power – not one rooted in dirty fossil fuels of the past.”

Greenpeace added: “Rees-Mogg is the last person who should be in charge of the energy brief, at the worst possible moment.

“Appointing him to the brief now suggests the Conservatives have learned nothing from some years of energy policy incompetence.”

Some of the harshest criticism came from Ed Davey, leader of the opposition Liberal Democrats who helped shape the UK’s current renewable policies as energy secretary in the first half of the last decade, in coalition with the Conservatives.

“For years Jacob Rees-Mogg has been on the wrong side of the argument. The last thing we need is another climate dinosaur in cabinet,” said Davey.

Truss is due on Thursday to make a major speech on energy policy with a focus on lowering costs for UK billpayers who are among the hardest hit in Europe by the current crisis.

Overwhelming renewables support

Rees-Mogg's appointment came as polling commissioned by industry body RenewableUK showed strong public support for building new renewables as a way to ease the energy crisis.

According to the research 77% of Britons think the new government should use new wind and solar farms to reduce electricity bills, and 76% support building renewable energy projects in their local area. Support is actually higher among Conservative voters, the polls show.

RenewableUK CEO Dan McGrail said: “These findings are wake-up call to every politician, including the new Prime Minister, that the overwhelming majority of people want to see new investment in renewables and are happy to see new wind and solar farms built in their local area to drive energy bills down.”