A spokesman said: "The government is not interested in where people go for their holidays, but is determined to identify people who pose a threat to our security, stopping known criminals and turning back illegal immigrants."
The UK Border Agency receives information on passengers from carriers. Part of the e-Borders scheme is to count people in and out of the country.
The agency checks people against "watch lists" using passport readers and iris scanners. In December, a hi-tech National Border Targeting Centre will be opened in Manchester. By the end of 2010 staff there will monitor most British and EU passengers and almost every foreign passenger travelling in and out of Britain.
By the end of this year, e-Borders will screen 60% of all passengers and crew movements in and out of the UK, checking each person against watch lists. This will rise to 95% by the end of 2010 and 100% by March 2014.
The government will do this using facial recognition technology, which sees the faces of passengers being scanned and compared to their biometric passports. Trials of the system are currently underway at Manchester and Stanstead airports, but new locations are still to be decided.
Other technologies are being introduced to combat border crime.
In April, new technology will be introduced to help detect drugs and other illegal goods. Fourteen mobile freight scanners are in use and have helped seize £260m worth of drugs since April last year.
Two new scanners will be added, and some of the older scanners will be upgraded and replaced. The Border Agency also uses dog teams, carbon dioxide detectors and heartbeat monitors to detect people, money and drugs.
The new technologies are part of a range of measures the government is introducing to raise the bar for foreign workers wishing to enter the UK, and "give domestic workers a greater chance of applying first for UK jobs".
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