A British doctor who is being sued for libel after criticising an American company’s research has pledged to turn the action into a test case for freedom of speech. Peter Wilmshurst, a consultant cardiologist at the Royal Shrewsbury Hospital, told The Times that he aims to use a public-interest defence to fight the claim from NMT Medical and establish the principle that scientists may engage freely in academic debate.

He said he was prepared to risk losing his home to take the case to trial because victory would set a precedent protecting other scientists from “legal bullying”.

Dr Wilmshurst said: “I have got a responsibility to fight this. There is a fundamental principle of science at stake here. People have to be free to challenge research.”

There is growing concern about the use of England’s draconian libel laws to stifle expert scrutiny of scientific evidence. Simon Singh, the science writer, has been sued for libel by the British Chiropractic Association over an article in which he questioned the evidence that spinal manipulation could treat childhood conditions such as asthma and colic.

Many scientific journals admit that they now seek legal advice before publishing some academic papers, and several websites have withdrawn scientific articles claimed as defamatory because of the prohibitive costs of defending such actions.

A petition to keep libel laws out of science has been signed by nearly 19,000 supporters, including Lord Rees of Ludlow, the president of the Royal Society; Sir Mark Walport, the director of the Wellcome Trust; and Sir David King, a former government chief scientist.

Jack Straw, the Justice Secretary, who spoke to Dr Wilmshurst last week, said that he was preparing reforms to the libel laws. “What concerns me is that the current arrangements are being used by big corporations to restrict fair comment, not always by journalists but also by academics,” he told The Sunday Times.

A further concern is the growth of “libel tourism”, fuelled by the greater ease of suing successfully in England than in the US, and the English courts’ willingness to accept claims from litigants with few connections to Britain.

A report published last week by English PEN, a writers’ charity, and Index on Censorship, which campaigns for freedom of speech, recommended reforms, including a requirement that 10 per cent of the circulation of a publication accused of libel must be in Britain for a claim to be heard here. It also suggests a £10,000 cap on damages and a requirement that plaintiffs prove that alleged defamatory statements are both false and damaging.

Dr Wilmshurt’s case began with his involvement in a study of a medical device made by NMT called Starflex, designed to close a type of hole in the heart known as a patent foramen ovale (PFO). The study investigated Starflex as a potential treatment for migraine, which is significantly more common among people with a PFO, but failed to find benefits.

At a cardiology conference in Washington in 2007, Dr Wilmshurst criticised NMT in relation to the research. His comments were reported by Heartwire, a website, prompting NMT to sue him.

Dr Wilmshurst and his solicitor, Mark Lewis, will meet NMT’s legal team next month for mediation. If no deal is reached, the case is expected to go to trial.

Dr Wilmshurst said that he would settle out of court if NMT issued a statement recognising his right to criticise scientific research. “They always have the option of dropping the action and paying costs, but I wouldn’t be satisfied with that,” he said.

“We also want them to say they recognise my right to have said this. They should recognise that even though they don’t agree, this is an expert opinion and they shouldn’t have sued.”

Mr Lewis said: “There is a reason not to settle, which is that this case is of wider interest for all scientists, and for the public who relies on them to assess medical research.”

Libel law, Mr Lewis said, was having “not so much a chilling effect as a killing effect” on scientific debate, by making researchers think twice before challenging findings with which they disagreed.

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