The climate sceptic organisation founded by former chancellor Nigel Lawson is to set up a new campaigning arm, which would be free from charity regulations.

The Global Warming Policy Foundation, which is classified as an educational charity and thus covered by strict Charity Commission rules that restrict its ability to conduct political campaigns, said that the new non-charitable company would undertake "activities which do not fall squarely within the educational remit of the charity".

Similar structures are also used by some other non-profit organisations, because it gives them greater freedom in lobbying and in some commercial activities.

The new arm, to be called the Global Warming Policy Forum, will share the same website and initials and publish reports and research papers, as well as organising lectures and debates on science and policy. In particular, it will put out news articles and opinion columns through a section of its website.

If the Charity Commission agrees with the restructuring, the new organisation will start operating by the end of July.

Bob Ward, policy and communications director at the Grantham Research Institute at the London School of Economics, last year complained to the Charity Commission, over what he saw as the dissemination by the GWPF of "misleading and inaccurate" information. Charity Commission rules require organisations granted charitable status – which allows them, and their donors, to benefit from favourable tax treatment – to ensure that any information they put out is fair and as accurate as possible.

Ward said: "I think it is apparent that this move is designed to get around Charity Commission rules that specify that it must not disseminate inaccurate information. It is a deeply cynical move by the Foundation to avoid any formal requirement that they should stop misleading the public with inaccurate information. However, I hope now that it will be more obvious that when Lord Lawson speaks about climate change, it is as a campaigner rather than as an expert. And at least its secret donors will no longer be able to claim tax relief on funding the Foundation's political propaganda."

Greenpeace, which was named by the GWPF as an organisation that operates a campaigning arm as well as its core charity, told the Guardian: "They do say imitation is the sincerest form of flattery." But he said that if Lord Lawson really wants to emulate Greenpeace's structure he should be open about where his funding comes from and "root his political campaign in the reality of climate science."

The GWPF does not disclose the names of organisations or individuals who provide its funding, but says that fossil fuel companies are not among them.

Benny Peiser, of the GWPF, said Ward's complaints had not come up in the discussions with the commission. He added: "Our charitable status has not changed and we will continue with our objectives, only more effectively now."

• This article was amended on 13 May 2014 to include a statement from the Global Warming Policy Forum.