As part of its crackdown on extremist groups in the wake of recent bombings, Britain on Wednesday unveiled a plan under which foreigners considered to be promoting terrorism can be deported or excluded from the United Kingdom.

The grounds set for deportation mentioned in the list of "unacceptable behaviour" released by Home Secretary Charles Clarke included fomenting, justifying or glorifying terrorist violence, seeking to provoke terrorist acts and fostering hatred that might lead to inter-community violence.

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They include radical preaching and publishing websites and articles intended to foment terrorism. Articles already published, as well as speeches or sermons already made, will also be covered in the list.

The measures were announced less than a week after controversial cleric Omar Bakri Mohammed left Britain for Lebanon and UK said he would not be allowed to return.

Others who could come under scrutiny include, Mohammed al-Massari, the Saudi Arabian dissident whose website carried images of attacks on British troops in Iraq.

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"The terrorist threat facing the UK remains real and significant and it is right that the government and law enforcement agencies do everything possible to counter it," Clarke said.

He said he had an obligation to "stop people coming into the country to get young people, in particular, to behave in the appalling way we saw in July."

Unveiling the results of the review, he said the first deportation could happen "very quickly-in the next few days.

Individuals who seek to create fear, distrust and division in order to stir up terrorist activity will not be tolerated by the government or by our communities."

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'By publishing the list I make it absolutely clear that these are unacceptable behaviours and will be the grounds for deporting and excluding such individuals from the

UK,' Clarke said in a statement.

He said it includes views expressed through written, published or distributed material and websites as well as public speaking or preaching but was quick to point out that his expanded poweres were 'not intended to stifle free speech or legitimate debate about religions or other issues'.

As part of a slew of measures to crackdown on 'preachers of intolerance and hatred', a new database will be drawn up of foreign-born radicals accused of encouraging acts of terrorism, he said.

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The global database will list those who face automatic vetting before being allowed into the UK.

He said authorities were already considering a number of names of people engaged in such unacceptable activities.

"All our foreign posts throughout the world are looking at their particular country...and of course, we have got the names that are widely in the public domain at the moment."