Terror level lowered to 'substantial' from 'severe'

The official estimate of the threat from international terrorists has been lowered. The assessment of the likelihood of a terror attack against the UK was downgraded from "severe" to "substantial", said the Home Secretary Alan Johnson.

The likelihood of an attack in the near future has shifted from "highly likely" to a "strong possibility". But Mr Johnson said the country still faces a "real and serious" threat from terrorists and urged members of the public to remain vigilant.

The Joint Terrorism Analysis Centre (JTAC), a unit within MI5, sets the level based on an analysis of intelligence. The assessment covers potential attacks by al-Qa'ida or linked extremist groups. There are five levels of threat, ranging from "low", meaning an attack is unlikely, to "critical", when an attack is expected imminently.

Mr Johnson said: "The Joint Terrorism Analysis Centre has reduced the threat to the UK from international terrorism from 'severe' to 'substantial'. This means that an attack on the UK is a strong possibility. JTAC make their judgements based on a broad range of factors, including the intent and capabilities of international terrorist groups in the UK."

The shift means the threat level is now at its lowest since May 2005 when it was set at "substantial" – two months before the July 7 bombings. At the time the threat was rated under a slightly different system and not made public. The threat level was last at "critical" in June 2007, following the attack on Glasgow Airport and the failed car bombings in central London.