The House of Lords has voted 150 to 54 to amend Section 5 of the Public Order Act 1986 and therefore to end the criminalisation of insults.
The move has been welcomed by civil liberties advocates who are members of the Reform Section 5 campaign coalition.
The vote in the second chamber represents a significant defeat for the Home Secretary and the Conservatives within the Westminster coalition government.
The amendment will now go to the House of Commons, where a poll earlier this year found that 62 per cent of MPs believe it is not the business of government or the law to criminalise insults.
"This is a sweeping victory for free speech and civil liberties. It is all the more significant given the disgraceful opposition to reform by the Labour and Conservative front benches," commented human rights campaigner Peter Tatchell.
He continued: “The criminalisation of insults is far too subjective and constitutes a dangerously low prosecution threshold. Anyone who values free speech and robust debate should welcome the reform of Section 5.
“The Section 5 ban on insults has been abused to arrest people protesting peacefully against abortion and campaigning for gay equality and animal welfare. Other victims include Christian street preachers and critics of Scientology.
“What constitutes a criminal insult is completely elastic and subjective, which is why people have been arrested for criticising homosexuality and Islamist extremists.
“Freedom of expression is one of the most important of all human rights. It should be only restricted in extreme circumstances. The open exchange of ideas - including unpalatable, even offensive ones - is the hallmark of a free and democratic society.
“The insults clause of Section 5 menaces free speech. It has been misused too many times to suppress freedom of expression," said Mr Tatchell.
Reform of the law is supported by the present and previous Director of Public Prosecutions, the former Lord Chancellor Lord Mackay, the Independent Police Complaints Commission, Liberty, Justice, the Equality and Human Rights Commission and the Joint Parliamentary Committee on Human Rights, as well as the Reform Section 5 campaign. The Association of Chief Police Officers has no objection to reform.
Section 5 of the Public Order Act 1986 criminalises “threatening, abusive or insulting words or behaviour...within the hearing or sight of a person likely to be caused harassment, alarm or distress thereby.”
Comments Mr Tatchell: “There is no requirement to prove that anyone has been harassed, alarmed or distressed. The mere likelihood is sufficient to secure a conviction. Moreover, an offence is committed regardless of the offender’s intention. Innocently intended words can result in a criminal record. The police and the courts can decide if a person might feel insulted. This is a threat to free speech.
"This legislation has been on the statue books 26 years. It was initially introduced to tackle football hooliganism and public disorder. The legislation is now being misused to criminalise people for trivial comments, including those who were simply expressing their views or beliefs."
On Monday 10 December, the Reform Section 5 campaign staged a protest outside the Home Office featuring Peter Tatchell dressed as a police officer, with a pantomime horse and a student. They were highlighting the case of an Oxford student who was arrested in 2005 under Section 5 for joking that a police officer's horse was gay.