An al Qaeda suicide attack against London may be imminent.

Police officers in the capital have been placed on alert and have been given fresh instructions on spotting and tackling suicide bombers.

Patrick Mercer, a Conservative home affairs spokesman, said: "It is clear attacks are being planned in this country. We mustn't let our guard drop.

"Several of my visits over the past few weeks have shown me that little has been done in the NHS, the fire service, the police and local authorities to prepare for such attacks."

Today's Mail and Mirror report that police have been ordered to "shoot to kill" suicide bombers.