The organisation Muslims Against Crusades will be banned from operating in the UK from midnight, the Home Secretary has said.
Theresa May said she was satisfied the group was "simply another name for an organisation already proscribed under a number of names" including Al Ghurabaa, The Saved Sect, Al Muhajiroun and Islam4UK.
"The organisation was proscribed in 2006 for glorifying terrorism and we are clear it should not be able to continue these activities by simply changing its name," she said.
Mrs May said on Thursday: "I have today laid an order which will proscribe Muslims Against Crusades from midnight tonight.
"This means being a member of, or supporting the organisation, will be a criminal offence."
Anjem Choudary, who describes himself as a press spokesman for the extremist group, said the decision was a "bid by the Government to cover up the truth".
He said he did not know if a "Hell for Heroes" demonstration against Remembrance commemorations would now go ahead.
Responding to the Government's announcement, he said: "I think it is an abject failure of democracy and it is a victory for Sharia Muslims. The truth is something the Government would rather silence."
The demonstration was due to take place outside the Royal Albert Hall, the same location where a poppy was burned last year.
No Muslims Against Crusades members were arrested in the build-up to the announcement from Mrs May.
The home secretary, Theresa May, said she was satisfied Muslims Against Crusades was another name for an already banned organisation.
The home secretary, Theresa May, has ordered Muslims Against Crusades, an Islamist group which is planning to disrupt Friday's Armistice Day ceremonies, be banned from midnight.
The organisation, which burned two large poppies near the Royal Albert Hall in London on Remembrance Day during the minute's silence last year, is a renamed successor to the already banned Islam4UK and other proscribed organisations. Anjem Choudary is a leading figure in both groups.
The immediate ban is part of the government's new drive to proscribe organisations that glorify terrorism in addition to those having direct links to terrorist groups.
The ban will make membership of Muslims Against Crusades a criminal offence.
May said: "I am satisfied Muslims Against Crusades is simply another name for an organisation already proscribed under a number of names including Al Ghurabaa, The Saved Sect, Al-Muhajiroun and Islam4UK. The organisation was proscribed in 2006 for glorifying terrorism and we are clear it should not be able to continue these activities by simply changing its name."
A parliamentary order was laid at Westminster on Thursday morning implementing the ban.
The group has often clashed with the English Defence League since it was set up last year. It has staged a pro-Bin Laden rally outside the US embassy. On the anniversary of 9/11 its members burned US flags and chanted through megaphones outside the embassy, disrupting a minute's silence by mourners at the nearby September 11 memorial garden.
A statement on the group's website said this year's Armistice Day would be marked by "a total lack of silence" by the Muslim community in Britain to highlight the continuing "atrocities" in Iraq and Afghanistan and the "brutal torture concentration camps of Guantánamo Bay and Abu Ghraib".
The "hell for heroes" protest planned for Friday was also scheduled to take place outside the Royal Albert Hall.
The Home Office said the decision was based on an assessment of the group's involvement in the glorification of terrorism and the evidence that Muslims Against Crusades is another name for an already proscribed terrorist organisation.
The ban, which has been evoked under the Terrorism Act 2000, also makes it a criminal offence to "arrange a meeting in support of a proscribed organisation, or to wear clothing, or to carry articles in public which arouse reasonable suspicion that an individual is a member or supporter of the proscribed organisation"..