The couple, from Washington, Tyne and Wear, said they had never left the UK and only got their passports last year.

BBC: Washington lottery winners have no plans to quit jobs

On the issue of passports, Mr Jenkins said he anticipated it would not be a problem for Scots living in other parts of the UK to have a two passports.

BBC: Scottish independence: Yes chief praises small economies

But Labour claims the issuing of horse passports in the UK is fragmented, as there are 75 approved issuing organisations in the UK, with no national database to track the information.

BBC: Contaminated horsemeat sold for food, FSA admits

Defra told BBC News that around 1.3 million passports have been issued in the UK with more than 64, 000 being issued in 2011.

BBC: Science & Environment

The number of forged passports detected at ports and airports across the UK has almost halved in the past five years.

BBC: Fewer fake passports being found by UK's border force

The details of those who have should have handed in their passports have been passed to port authorities in the UK and Europe, according to the Home Office.

BBC: NEWS | UK | More England fans flood Frankfurt

The UK will move towards an integrated electronic border security system, linking biometric passports and visas with electronic checks on entry and exit, helping to track and intercept terrorists and criminals and to stop illegal immigration.

BBC: Key points: Brown speech

She called for a tightening of microchipping and the registering with passports of horses destined for slaughter for food production in the UK. She repeated statistics showing that 6% of horses killed in Britain later tested positive for the drug bute, which is not cleared for human consumption.

BBC: Horsemeat scandal: 'Too trusting' on meat supplies

Interpol names the US, UK and UAE as the three most active countries when it comes to screening passports.

BBC: How safe is your passport?

The UK is already investigating claims that six of those involved in the attack were travelling on fake British passports.

BBC: Urgent question