Defence sources said the order had been given that uniform should not be worn by those travelling alone, or on public transport as a “common sense precaution” immediately after the killing

A source stressed the order was temporary while investigations into the killing carried on and the decision would be reviewed in the next few days.

Col Richard Kemp, who commanded British forces in Afghanistan, said it would be a mistake to reinstate an earlier permanent bar on military personnel wearing uniforms in public. That ban was put in force because of an IRA campaign in the 1970s and 1980s to target personnel in Britain, Germany and Holland.