MPs approved the Defamation Bill, which aims both to reform libel laws in England and Wales and protect freedom of speech, at second reading on 12 June 2012.
The government believes the legislation will prevent trivial libel cases reaching the courts and to make it easier to identify internet "trolls" who post abuse anonymously on websites.
Labour MP Helen Goodman said the bill would encourage good journalism and Conservative MP Amber Rudd sought to highlight the "unity" across the House in support of the bill.
Currently, a person suing for defamation does not have to prove the words they are complaining about have caused them actual damage.
Under the bill, claimants will have to show their reputations have suffered, or will be likely to suffer, "serious" harm before suing for defamation.
A single-publication rule is also included in the legislation, so that the one-year limitation period in which a libel action can be brought would run from the date of the first publication of material, even if the same article is subsequently published on a website on a later date.
The bill, which applies to England and Wales, replaces the common law defences of justification and honest comment with new statutory defences of truth and honest opinion.
The so-called Reynolds defence of responsible journalism published in the public interest also gets statutory recognition.
Statements published in peer-reviewed scientific journals will be exempt from defamation law, unless they can be shown to have been made with malice.
The bill also aims to end "libel tourism" by ensuring legal proceedings only take place in England and Wales if that is the most appropriate jurisdiction.