The technology to be used in proposed UK identity cards is to be put on trial from next month.
A compulsory ID card is unlikely for some years
Ten thousand volunteers will have their fingerprints or iris scans put on cards during the six-month test.
Plans for a national identity scheme were part of last week's Queen's Speech after a battle in the cabinet.
The scheme will be rolled out through passports and driving licences - but a decision on whether to make the cards compulsory will not come until 2013.
The trial is being run by the UK Passport Service and will focus on the enrolment process for biometrics, which are due to become compulsory for people renewing passports from 2007-8.
It will time how long it takes to take fingerprints and iris scans from each person, as well as exploring the problems of building a database.
The test runs will happen at four fixed sites, including a passport office, as well as in mobile units.
Pollster Mori is involved in ensuring the volunteers are representative of the UK population, including disabled people and others who could face difficulties enrolling.
The trial is also designed to help estimate the total costs of a national ID card scheme. The current official estimate is £3.1bn.
But the Home Office is not saying how much the trial itself will cost because it is "commercially sensitive".
Home Office Minister Beverley Hughes said: "We are moving ahead with the development and testing of this cutting-edge technology.
"This large-scale trial will play an important part in that process."
The DVLA, which issues driving licences, will also be involved in the trial.
Biometric passports will start being issued in 2005.
Ministers say secure identity cards can protect against illegal working, immigration abuse and organised crime.
But critics say criminals will be able to gain passports with a false name but "genuine" fingerprints or iris scans.
And they argue the money being devoted to the scheme would be better spent on extra policing.