Climate science deniers are lining up a political offensive in Britain after a US lobby group opened a UK branch which is already working with Nigel Farage.

The Reform UK leader was the guest of honour at the launch of Heartland UK/Europe, which is to be headed by a former leader of Ukip and climate denier.

The former prime minister Liz Truss was seen at the event in London, alongside current Tory MPs Andrew Griffith, who is the shadow trade minister, and Christopher Chope.

The establishment of this UK branch of the Heartland Institute – which has links to the incoming Trump administration and has drawn on funding from companies including ExxonMobil and wealthy US Republican donors – comes as Farage seeks to make hostility to net zero a centrepiece of Reform’s electoral pitch. Reform MPs have used speaking time in parliament to push for the scrapping of net zero targets and to call for new coalmines.

Heartland has made some extreme and incorrect comments on climate. In the past, it has compared people who believe in global heating to the Unabomber, the US terrorist jailed for killing three people and injuring many others. It has also wrongly claimed heatwaves are not increasing in the US because of the climate crisis.

The Heartland Institute president, James Taylor, said: “During recent years, a growing number of policymakers in the UK and continental Europe have requested Heartland establish a satellite office to provide resources to conservative policymakers throughout Europe. With our UK and European launch, we aim to fulfil this requested impact throughout Europe.”

Lois Perry, who led Ukip until June and has described the climate emergency as “a scam”, will head the UK branch. She has made regular appearances on GB News, where she has played down the existence of, and threats posed by, the climate crisis.

The launch in December was held in the exclusive Brooks’s private members club in Mayfair, one of the few remaining gentlemen’s clubs that does not admit women.

Farage has struck up a close relationship with the group. In an interview in October with Taylor, he claimed the “minority position” against net zero was “gaining ground”.A leading UK-based climate research institute said Heartland had a track record of promoting extreme versions of climate science denial in the US.

Bob Ward, the director of communications at the LSE’s Grantham Research Institute on Climate Change and the Environment, said: “Heartland no doubt feels emboldened by the prospect of a new Trump administration that is promising to carry out an ideological purge of anything related to climate action.”.

The development was described by the Green party co-leader Adrian Ramsay as a move to “import dirty US climate-denying money into British politics”.

“That Farage seems so willing to sell out British interests and front climate denial for his own short-term gain should alarm us all,” he added.

Griffith said: “In any year, I attend hundreds of external events with business organisations and thinktanks, none of which automatically imply my endorsement. A successful UK business environment requires competitive energy costs, something this socialist government seems not to understand.”

Reform UK, the Heartland Institute and Truss have been approached for comment.