“Britain’s terrorist threat level was raised tonight from ‘substantial’ to ‘severe’ – meaning that counter-terrorism agencies believe an attack is ‘highly likely’.

The measure was approved at a meeting of the Government’s Cobra emergency committee and announced by Alan Johnson, the Home Secretary.

“Acting on intelligence failures exposed by the attempted bombing of a Detroit-bound airliner on Christmas Day, Prime Minister Gordon Brown announced a major tightening of British aviation security measures on Wednesday, including the creation of a new ‘no-fly’ list of terrorist suspects similar to one maintained by the United States.”