Libel laws are “making a mockery” of the justice system and “stifling” scientific debate, Liberal Democrat leader Nick Clegg has said.
He blamed “draconian and unbalanced” legislation for a growth of “libel tourism”, in which foreign plaintiffs lodge cases in British courts.
Scientists needed more freedom of speech to protect them from “dubious” research, he said.
The government has ordered a review of defamation law in England and Wales.
There is concern that strict libel laws are being used by wealthy people from the UK and abroad to bully those trying to hold them to account.
‘Threatens the public’
In his speech to the Royal Society, Mr Clegg said: “Of course people have the right to protect their reputations from damaging and false statements made recklessly, irresponsibly or with malice.
“But scientists must be allowed to question claims fearlessly, especially those that relate to medical care, environmental damage and public safety, if we are to protect ourselves against dubious research practices, phoney treatments and vested corporate interests.
“English libel law as it stands is obstructing that process and threatens the public good as a result.
“The prospect of a costly, protracted legal battle hangs over journalists, editors and academics seeking to ask basic questions about the evidence for practices they believe may put people at serious risk.
“Our libel law and practice have turned a country once famed for its traditions of freedom and liberty into a legal farce where people and corporations with money can impose silence on others at will.”
Mr Clegg said he believed in “raucous freedom of speech, not gagging orders”.
He added: “Libel tourism is making a mockery of British justice, with foreign plaintiffs able to bring cases against foreign defendants when the publications in question may have sold just a handful of copies in England.”
A review of libel laws, ordered by Justice Secretary Jack Straw, is due to be completed by the spring.
Freedom of speech campaigners have suggested that libel payouts could be capped at £10,000, with apologies being the main remedy.
There have also been calls for the burden of proof to be shifted, so claimants have to demonstrate they have suffered damage.