Freedom of speech will be given more protection and the libel law reformed in England and Wales, it has been announced in the Queen's Speech.
Claimants will have to show they have suffered serious harm before suing for defamation, under the Defamation Bill.
It is understood the bill is intended to ensure a "fair balance" between freedom of expression and protection of reputation.
The presumption in favour of a jury trial will also be removed.
It is understood the bill is likely to be published on Friday.
Currently, a person suing for defamation does not have to prove the words they are complaining about have caused them actual damage, it is enough for the courts that they might.
According to the Ministry of Justice, the new bill will also ensure the threat of libel proceedings is not used to "frustrate robust scientific and academic debate".
There will be a defence for the media of "responsible publication on matters of public interest".
The bill will provide greater protection to operators of websites hosting user-generated content, as long as they complied with the necessary procedure to "resolve any dispute" directly with the author of the material concerned.
The draft bill, published in March last year, also aims at addressing "libel tourism" by tightening the test to be applied by the courts in relation to actions involving people who are not domiciled in the UK or EU member states.
The Conservatives, Labour and the Lib Dems all committed themselves to reviewing libel law in their election manifestos.
The Libel Reform Campaign, made up of Index on Censorship, English Pen and Sense About Science, welcomed the announcement but said there was "still work to be done".
A spokesman for the campaign, which has been demanding the legislation since 2009, said the bill would pave the way to end libel tourism and protect free expression for journalists, writers, bloggers and scientists around the world.
Sense About Science managing director Tracey Brown said: "This opens the way to developing a law guided by public interest not powerful interests."
Cardiologist Dr Peter Wilmshurst, who was sued by an American medical device company, said: "Patients have suffered because the draconian defamation laws were used to silence doctors with legitimate concerns about medical safety."