LONDON - Nearly 200 trained Al-Qaeda terrorists are on the loose in Britain, the former head of London's Metropolitan Police said Sunday in an alarming twist to a heated debate over controversial new anti-terrorist legislation.
Writing in the News of the World newspaper, Sir John Stevens -- who as Britain's most senior police office had unique access to top-secret intelligence -- said there were "at least 100 Osama bin Laden-trained terrorists" in the country.
"The number is probably nearer 200," Stevens added. "The cunning of Al-Qaeda means we can't be exact, but they would all commit devastating terror attacks against us if they could, even those born and brought up here."
He said their presence made it all the more important for the proposed Prevention of Terrorism Act -- now making its way through parliament -- to be enacted as soon as possible.
Critics say the legislation, which would allow terrorism suspects to be subject to house arrest, curfew, electronic tagging and bans on Internet and telephone use, rides roughshod over civil liberties.
But Stevens, who stepped down as Metropolitan Police commissioner earlier this year, said: "Any delay can only give comfort to the terrorists in our midst waiting to be attack us."
"Whatever the human rights lobby says, we should (enact the new law) for the safety of the vast majority of people in this country. The world has changed. We need to take new steps for new threats."
The Prevention of Terrorism Act faces a tough review in the unelected upper House of Lords this week, after it squeaked through the House of Commons last Tuesday by a 272-219 vote amid a revolt among backbench Labour lawmakers.
It is meant to replace the Anti-Terrorism, Crime et Security Act, which was struck down by the Law Lords, the nation's supreme court, last December because it allowed foreign terrorism suspects indefinitely without trial.
Al-Qaeda, which engineered the September 11 attacks in the United States in 2001, is regarded by the Home Office as "the most significant terrorist threat to the UK and to UK interests overseas".
His latest warning, in the first of a series of columns for Britain's best-selling Sunday newspaper, followed a claim by Blair last Monday that there are "several hundred" would-be terrorists in Britain plotting attacks.
"There are several hundred of them in this country who we believe are engaged in plotting or trying to commit terrorist acts," Blair -- who is gearing up for an expected May general election -- said on BBC radio.
Stevens' successor Sir Ian Blair has meanwhile said that terrorists might try to carry out an attack during the upcoming election campaign, as they did a year ago when they bombed Madrid commuter trains before Spanish elections.
Terrorism returned to the front pages in Britain this past week when a British-born Muslim, Saajid Muhammad Badat, 25, pleaded guilty in a London court to conspiracy to blow up an airliner for Al-Qaeda.
He was supposed to have carried out a suicide bomb attack on a US-bound flight in December 2001 in tandem with Richard Reid, who tried but failed to blow up a plane in mid-air with explosives hidden in his shoes.
Reid, who is also British, is now serving a life sentence in a US prison.
On Monday, three people arrested last Tuesday in Coventry, in the west Midlands, are to appear in a London court on suspicion of financing terrorism. One of the accused is said to be a leader of an Islamic fundamentalist group in the disputed Indian state of Kashmir.

03/06/2005 12:39 GMT