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.