Britain’s net zero policies and the energy secretary, Ed Miliband, have come under fire at a conference of conservatives, rightwing populists and wealthy US backers linked to Donald Trump.

The energy policies pursued by the British government were described as a “tragic mistake” by Trump’s energy secretary, one of a number of officials from the US administration attending the event.

More than 4,000 delegates from 85 countries – ranging from the Conservative leader, Kemi Badenoch, through to US anti-abortion activists and representatives of European far-right parties – are attending this year’s Alliance for Responsible Citizenship (ARC) conference in London.

Dubbed by some as an “anti-woke Davos,” themes being championed from the stage at the Olympia conference centre included libertarian hostility to green economic policies, social conservative causes such as opposition to abortion and also opposition to multiculturalism.

Speakers later this week include US state department officials who have sought to interfere in Britain’s abortion rights and debate around online safety regulations, while the Reform leader, Nigel Farage, will address the conference on Wednesday.

One of the key figures on Tuesday was Chris Wright, a former fossil fuel executive who was appointed by Trump as energy secretary. He described energy policies in Britain as a “tragic mistake” that had impoverished citizens.

Wright, who believes the threat from the climate crisis is exaggerated, predicted that a “change of leadership” in the UK would radically reverse energy policy and align it more with the US.

“Most of the major European countries are well aware of the energy mistake they have made and are trying to understand how they are going to pivot away from it,” said Wright, who joined the conference on one of the hottest days of the year in Britain as delegates inside sweltered.

Badenoch and other speakers at the event – which is being funded by a host of US fossil fuel interests, major Trump donors and anti-abortion groups – repeatedly hit out at the energy secretary, Ed Miliband, a villain for many at the conference.

Miliband, who has long been a hate figure for hard-right activists as the face of Britain’s net zero policies, has become the focus of increasing criticism on the right in recent weeks as he was mooted as a possible chancellor in a government led by Andy Burnham.

Speaking to Philippa Stroud, a Tory peer who was one of the co-founders of the ARC conference along with the Canadian psychologist Jordan Peterson, Badenoch said that there had been a “villain in Britain’s deindustrialisation.”

“His name is Ed Miliband and he has made our country poorer,” she said, to applause.

“We need to make sure that this man should not be let anywhere near the levers of power, not the energy department or anywhere else.”

While ARC is also heavily backed by the owners of GB News – hedge fund manager Paul Marshall and the Dubai-based investment group Legatum – a list of donors for this year’s conference shows that it has received financial backing from powerful US donors with close ties to the Trump administration.

Analysis by the climate investigations outlet DeSmog found that the donors include Anthony Pratt, an Australian-born billionaire who reportedly donated $14m to the Trump-supporting Make America Great Again Super Pac, and a further $1.1m to the president’s inaugural fund.

He is joined on the donors list by the American fossil fuel companies Howard Energy Partners (HEP) and Heyco Energy Group, both of which also helped to fund last year’s event. HEP is one of the largest energy infrastructure companies in the US; its CEO Mike Howard, a Republican donor, was appointed to Trump’s National Petroleum Council in February this year.

Aside from hostility to conventional narratives around the climate crisis, the event has also drawn together thousands of political activists and politicians from across Europe, the US and Australia who are hostile to immigration and multiculturalism.