English passengers making internal flights to Scottish airports are being asked to show their passports when they land, police have confirmed.

Officers are carrying out routine identity checks on domestic flights under terrorism legislation. This can mean forcing passengers to show passports or other photographic identification.

Those arriving on international flights are required to go through passport control, but domestic passengers are usually checked for photographic ID before boarding their plane.

The checks came to light after shadow home secretary Chris Grayling was asked to produce his documents when he arrived at Glasgow Prestwick airport on an internal flight.

He described the procedure as "utterly and completely unacceptable".

"Do we want to end up with border check points at Gretna Green? Of course we need security but there has to be a balance,” he told the Daily Telegraph.

Mr Grayling was among five Conservative MPs who were asked for identification at the airport on Wednesday.

The Terrorism Act 2000 gives police forces the power to stop anyone for identification checks, which can include showing a passport. Strathclyde Police, which covers Prestwick, 30 miles south west of the city centre, said its officers use the legislation “proportionately”.

A force spokesman said: “'Police officers, similar to other Border and Law Enforcement Agencies, operate at UK Air and Sea Ports in furtherance of their role of protecting our communities.

"As part of their duties, police require to establish the identity of persons present at or transiting through a port and, in recognition of this, legislation is provided for that purpose.

“In particular, specific powers are afforded to police examining officers to require production of a passport, or other recognised identity document bearing a photograph. Strathclyde Police endeavour to apply these powers proportionately bearing in mind the threat levels that apply currently, particularly in respect of aviation.”

"Strathclyde Police endeavour to apply these powers proportionately bearing in mind the threat levels that apply currently, particularly in respect of aviation."

A spokesman for the Metropolitan Police, which patrols Heathrow and City airports in London, confirmed it also used the powers, adding: "From time to time we to stop people and look at their travel documents. It’s not that unusual.”

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