Searches could be carried out according to race, ethnicity, age and gender – a move certain to anger civil rights groups fearing Muslims will be disproportionately targeted.

The examinations will also check for criminal convictions, immigration problems and links to terror suspects.

But under the prospective rules people could find themselves placed on enhanced Home Office no-fly lists, which will see them turned away when they arrive at the airport.

Alternatively, they will be added to a larger list of those who should be subject to special measures such as enhanced screening.

Many of the passengers will not know why they are being put through rigorous full body searches and other checks.

More controversially, Home Secretary Theresa May has refused to rule out the introduction of passenger profiling.