Britain had recently raised its terrorism threat level to the second highest level of 'severe'. (AFP)
Birmingham:
Britain's interior minister on Tuesday proposed measures to ban extremist groups and curb the activities of radical Islamist preachers even if they have committed no crime, in a move denounced as "wholly wrong" by campaigners.
"Not all extremism leads to violence and not all extremists are violent but the damage caused by extremism to our society is reason enough to act," Theresa May told the annual Conservative party conference in Birmingham.
"We must face down extremism in all its forms. We must stand up for our values," she told delegates to loud applause, as officials briefed journalists on the proposals to be enacted if the Conservatives win a 2015 general election.
"I want to see new civil powers to target extremists who stay just within the law," she said.
"Extremism Disruption Orders" would allow British courts to restrict the activities of individuals to prevent the risk of violence and public disorder, media reported.
They could be banned from speaking at public events, taking part in protests or speaking through the media -- a proposal likely to prove controversial because of memories of a BBC ban on Irish republican leader Gerry Adams from Sinn Fein.
They could also be ordered to submit any material to the police for vetting before it is put onto the Internet.
The "banning orders" would allow groups considered to be outlawed even if they did not pose a terrorism threat, including on the grounds of being a "threat" to democracy.
Membership of such groups would then become a criminal offence.
Emma Carr, director of Big Brother Watch, a civil liberties think tank, said the policies were the "thin end of the wedge".
"In a democratic country, it is wholly wrong for people to be labelled an 'extremist' and face having major restrictions placed on their freedom without facing a due legal process and a transparent and accountable system," Carr said.
"The Home Secretary must think very carefully about the international precedent that this policy would set and consider the potential consequences for members of the public."
Officials said the measures, which are to be included in the Conservative manifesto, would not only target Islamist extremists but could also be used against neo-Nazis or other hardline groups.
British police arrested radical Islamist preacher Anjem Choudary last week along with others suspected of links to a banned extremist group.
Choudary, who was released on bail, said the arrest was "politically motivated" and claimed it was linked to preparations for last week's vote in the British parliament on joining air strikes against Iraq.