Terror threat lowest level since 7/7 bombings

The decision to reduce the classi- fication from "severe" to "substantial" means that although an attack is be- lieved to remain a strong possibility, it is no longer regarded as highly likely.

The change, which follows a renewed assessment of the danger by the Government's Joint Terrorism Analysis Centre, was announced by Home Secretary Alan Johnson.

He cautioned that the country still faced a "real and serious" threat and urged the public to remain vigilant as police and MI5 continued to target extremists. "The Joint Terrorism Analy-sis Centre has reduced the threat to the UK from international terrorism from severe to substantial," he said.

"This means that an attack on the UK is a strong possibility. JTAC make their judgments based on a broad range of factors, including the intent and capabilities of international terrorist groups in the UK. We still face a real and serious threat from terrorists, and the public will notice little difference in the security measures in place. I urge the public to remain vigilant.

"The police and security services are continuing their thorough efforts to discover, track and disrupt terrorist activity."

The last time the official threat level - which can range across five classifications from "low" to "critical" - was set at substantial was in May 2005, two months before the July 7 bombings.

Since the London attacks it has generally remained at "severe", despite occasionally and briefly rising to "critical" -which means an attack is imminent - due to the extent of the per- ceived danger from the estimated 2,000 potential terror suspects identified by MI5.

The Joint Terrorism Analysis Centre, a unit within MI5, sets the level based on intelligence.

The assessment covers potential attacks by al Qaeda or linked extremist groups and the threat from dissident Republican and Loyalist terrorists in Northern Ireland.

The level is under constant review and can change quickly in response to events. It was previously kept secret, but was made public for the first time on 1 August 2006, when it was severe.

It was raised to critical on 10 August that year after a series of arrests over an alleged plot to blow up transatlantic aircraft, but lowered to severe again the following week.

The threat level was last at critical in June 2007 following the attack on Glasgow Airport and the failed car bombings in central London.

This month the UK's most senior counter-terrorism officer, John Yates, hinted at the possibility of a change.

He told the Association of Chief Police Officers' conference in Manchester: "I think there is a possibility the threat level may come down. It is logical because we cannot keep having it high unless the threat is there."