Two secret funders of Nigel Lawson’s climate sceptic organisation have been revealed. This is the first time anyone financing the group has confirmed their contributions. Both are linked to a free-market thinktank, the Institute of Economic Affairs (IEA), which has admitted taking funding from fossil fuel companies and has also argued against climate change mitigation.

Lord Lawson has steadfastly refused to name the funders of the Global Warming Policy Foundation since its inception in 2009, stating only that none have significant fossil fuel interests. The GWPF has become the most prominent climate sceptic group in the UK, but critics of the GWPF argue that funders’ names should be made public in the interest of transparency.

The names were uncovered by the investigative blog Desmog UK. Neil Record, the founding chairman of a currency management company Record and an IEA trustee, confirmed he has given money to the GWPF but said the amount was a “private matter”. Record gave the IEA £36,000 to support a seminar featuring Lawson in November 2009 and on the same day Lawson launched the GWPF. Record told the Guardian: “I personally regard the continuing contribution of the GWPF to the climate change debate as very positive in assisting balance and rationality in this contentious area.”

Lord Nigel Vinson, a wealthy industrialist and life vice-president of the IEA, has given the GWPF £15,000 according to Charity Commission records. “I am very proud to fund [the GWPF],” he told the Guardian. “You have to put a question mark over climate change if over the last 14 years the world has not got any hotter.” Scientists argue this “pause” in air temperatures is an illusion, based on cherry-picked data and ignoring the fact that over 90% of trapped heat enters the oceans.

Record and Vinson are the first GWPF funders to confirm their donations. Sir Michael Hintze, a major Conservative donor and hedge fund tycoon, was named by the Guardian in 2012 as a GWPF funder but has not confirmed or denied his GWPF link. Like Record, Hintze is an IEA trustee.

“Lawson has stubbornly refused to name his donors even though such secrecy must undermine the trust the public has in his climate denial thinktank,” said Brendan Montague, editor of DeSmog UK. “But now we might begin to understand why. The evidence suggests many of Lawson’s funders are associated with the radically neoliberal IEA, which has a long history of attacking climate science and regulations while accepting money from oil companies.”

Bob Ward, policy director at the LSE’s Grantham Research Institute on Climate Change, said: “It is not surprising to find such strong links with a right-wing lobby group, the IEA, which also promotes climate change denial. It is now crystal clear that the campaign by the GWPF against the UK government’s climate change policies is driven by right-wing ideological zeal rather than evidence-based reason.”

Lawson did not respond to a request for comment. In October 2012, he said his fundraising for the GWPF had started with his friends: “They tend to be richer than the average person and much more intelligent than the average person; that’s why they can see the flaws in the conventional wisdom.”

The GWPF, which is registered as an educational charity, launched a new campaigning arm on Monday which will not be restricted by Charity Commission rules on political campaigning. The Global Warming Policy Forum will, like the GWPF, be chaired by Lawson and Record is one of three board members.

“The new organisation will be able to conduct campaigns and activities which do not fall squarely within the foundation’s remit as an educational charity,” said a GWPF statement. In the statement, Lawson said: “This reorganisation will enable us to build on the progress of the past five years and make substantial further progress over the next five years which may well be decisive in the evolution of climate change policy.” The world’s nations have set a deadline of December 2015 for a global UN deal to tackle climate change.