Peter Tatchell has spoken out in defence of five Islamic extremists convicted of abusive language at a march in Luton last year.

The men were part of a march at a homecoming of British soldiers. Some of those present called troops returning from Afghanistan and Iraq “murderers” and “baby-killers”.

Tatchell, a gay rights campaigner who has spoken out for free speech in the past, acknowledged the homophobia of Muslim extremists but said people had “no right to not be offended”.

The five men were convicted yesterday under the Public Order Act of using threatening, abusive or insulting words or behaviour likely to cause harassment, alarm or distress. They were given two-year conditional discharges and were ordered to pay costs of £500 each.

Following the protest in March, Islamic cleric Anjem Choudary said at a press conference that gays should be executed. He was not prosecuted for the remarks. Today, home secretary Alan Johnson outlawed his group Islam4UK.

Tatchell said: “I abhor everything [the five men] stand for, but defend their right to freedom of expression. Even though what they said was offensive to many people, their right to speak their mind is one of the hallmarks of a democratic society.

“They want to destroy our democracy and freedoms. I want to defend these values. If we silence and criminalise their views, we are little better than them.”

He also called for some sections of the Public Order Act to be repealed, saying they “inhibit the right to free speech and the right to protest”.

Tatchell also supported the ‘free speech’ amendment in a bill designed to protect gays and lesbians from homophobic hatred, saying he was “content” with it and that free speech should be curtailed only when it incited murder or violence.

He also opposed the 2002 conviction of street preacher Harry Hammond. Hammond was arrested and convicted for holding up a placard saying “Stop Homosexuality”.

Tatchell described his conviction as a “grotesque misuse” of the Public Order Act.

However, he has called for sanctions on extremists who have been known to incite violence, such as imam Abu Usamah, who was shown in Channel 4′s Undercover Mosque documentary advocating the killing of gays and Muslims who leave their faith.