British Home Secretary Alan Johnson prepared an order Tuesday proscribing Al-Muhajiroun, also known as Islam4UK.

"Proscription is a tough but necessary power to tackle terrorism and is not a course we take lightly," Johnson said in a statement.

Al-Muhajiroun is already banned under two other names in the Terrorism Act 2000 -- Al-Ghurabaa and The Saved Sect. Johnson said the ban would now also apply to "a number" of the other names the group goes by.

The proscription does not need approval by Parliament, because it is considered an amendment to the act, said the Home Office spokeswoman, who did not give her name in line with policy.

"We are clear that an organization should not be able to circumvent proscription by simply changing its name," Johnson said.

The ban would prevent Al-Muhajiroun from having meetings or raising money, and it would make attending a meeting or being a member of the group a crime.

The group's leader, controversial British Muslim cleric Anjem Choudary, had threatened to stage a march in the town of Wootton Bassett as a protest against the war in Afghanistan.

Choudary said Sunday, after news of Johnson's plans, that the Home Office could not shut him down.

"We're not going to stop because the government bans an organization," he told CNN by phone. "If that means setting up another platform under another label, then so be it."

A ban "will just make the use of those names ... illegal. But Muslims everywhere are obliged to work collectively to establish the Islamic state and sharia law in the UK or wherever they are -- those things can't change," he added.

The bodies of British war dead are traditionally brought to Wootton Bassett, near a Royal Air Force base, when they are returned to the country.

Relatives and friends line the streets of the town along with local residents as hearses carry the flag-draped British remains, in scenes of public mourning widely reported by British media.

Choudary's proposal to march empty coffins through the streets drew fury and outrage.

The Home Office had said the march would be illegal if the group were banned, but the decision to proscribe the group was not caused only by its plans for the march, the Home Office said.

Choudary has never announced a date for his march and area police said he had not contacted them about it, as march organizers are required to do beforehand.

The Terrorism Act 2000 gives the home secretary the power to ban groups if the punishment is "proportionate and based on evidence that a group is concerned in terrorism as defined in the Terrorism Act 2000," according to the Home Office.