Workers in the City of London have been the first to receive new hi-tech identity cards, according to reports.
The cards, containing details of credit history, criminal records and immigration status, are being introduced to combat identity theft and illegal working.
Hundreds of staff at City banks, blue-chip companies and government departments are being issued with them, and thousands more are expected to follow.
Most of the cards are being issued to foreign nationals, who work as contract cleaners and restaurant and mailroom staff.
But critics condemned the scheme, which is being administered by a private-sector company, as an “unprecedented invasion of people’s privacy”.
The cards are linked to a database containing personal details gathered during a vetting process and held by private investigators Crocker Stolten. Unique identifiers such as fingerprints can also be added.
Former fraud squad officer Lionel Stolten, the man behind the scheme, told the Evening Standard: “Companies need to know who is entering their buildings, and that those people really are who they say they are – especially major corporations which hold sensitive information.”