Page last updated at 09:17 GMT, Saturday, 23 January 2010  UK
terrorist threat level raised to 'severe'  Alan Johnson: "The
number one job of the government is to keep the public safe"
Mr Johnson refused to say it was linked to the failed Detroit
airliner bombing, and said the government would not reveal
specific intelligence details.  The home secretary stressed
there was no intelligence to suggest a terrorist attack was
imminent.  'Real threat'   Mr Johnson said JTAC kept the threat
level under constant review, making its judgments based on a
broad range of factors including the intent and capabilities of
international terrorist groups in the UK and overseas.   Low -
attack is unlikely Moderate - attack is possible, but not likely
Substantial - attack is a strong possibility Severe - attack is
highly likely Critical - attack is expected imminently  The home
secretary said the new level meant people needed to be "more
aware".   Mr Johnson said: "We never say what the intelligence
is and it would be pretty