An attempt by an anti-gay Muslim preacher to hold a march in a British town may be blocked by home secretary Alan Johnson.

Islam4UK, headed by Anjem Choudary, says it plans to march through Wootton Bassett, a town famous for honouring soldiers killed abroad.

Islamist extremists held a protest in March in Luton against soldiers returning home from Iraq. They held signs calling soldiers ‘murderers’ and baby killers’. Nine people from an opposing group, called United People of Luton, were arrested after attacks on Asian shops.

Following the Luton march, Choudary launched a vitrolic attack on gays in which he said that they should be stoned to death.

He said last week that 500 Muslim extremists would march through the Wiltshire town with coffins symbolising Muslims killed in Iraq and Afghanistan.

The former lawyer, who lives on benefits, has frequently called for Sharia law and said adulterers should be stoned to death. He is the UK head of the banned terrorist group Al-Muhajiroun.

He has said the march will be peaceful, although there are fears it could become more violent than March’s protests. The right-wing English Defence League has said it will “descend” upon Choudary’s home and demonstrate outside his closet mosques if the protest is held.

Choudary has not applied for police or council permission for the march and has given no intended date, suggesting it could be a publicity stunt.

Home secretary Alan Johnson said he would not hesitate to block it if requested to do so by local authorities.

In a letter to families of soldiers killed abroad, he wrote: “It is worth reminding those who are still not blinded by the media propaganda that Afghanistan is not a British town near Wootton Bassett but rather Muslim land which no one has the right to occupy, with a Muslim population who do not deserve their innocent men, women and children to be killed for political mileage and for the greedy interests of the oppressive US and UK regimes.

“The procession in Wootton Bassett is therefore an attempt to engage the British public’s minds on the real reasons why their soldiers are returning home in body bags and the real cost of the war.”

Prime minister Gordon Brown said he was “appalled” at the plans, adding: “Wootton Bassett has a special significance for us all at this time, as it has been the scene of the repatriation of many members of our armed forces who have tragically fallen.

“Any attempt to use this location to cause further distress and suffering to those who have lost loved ones would be abhorrent and offensive.”

Progressive British Muslims warned that the group were homophobic and expressed concern that Islam4UK was a front for the banned group Choudary is the UK head of.

Selman Ansari, a board member of Progressive British Muslims said: “We’re concerned that terrorist organisations are dodging their bans by simply reforming under a new name. We can’t let the extremists intimidate people and spread their lies within the British Muslim community. I call upon the police to investigate whether Islam4UK is just Al-Muhajiroun by another name.”

A Facebook group set up to protest against the march currently has more than 350,000 supporters.