Ministers have been accused by Labour of encouraging illegal immigrants by ending the practice of fingerprinting those caught trying to enter the UK via the Channel Tunnel.
Immigration Minister Damian Green said the record had proved of little value in practice and officials would now have more time to search vehicles.
But Shadow Home Secretary Yvette Cooper attacked the change and said it sent a signal to stowaways that they should "feel free to keep trying" to enter the UK. Border security has been under the spotlight since it emerged last year that border controls for non-EU nationals had been relaxed - leading a top official to quit.
Mr Green confirmed the change of policy in a letter to Tory MP Roger Gale after he was alerted by a constituent. He said that while fingerprints could identify previously discovered illegal immigrants, it was "of limited value in helping to secure their removal" if they got into the UK.