The Home Office says its plans to introduce national ID cards are still on track, despite protests from one of its key initial target groups, airline pilots.
The British Airline Pilots' Association (Balpa) said pilots objected to being forced to take the card.
The pilots objected to their freedom of choice being taken away, a Balpa spokesman told Computer Weekly.
The government initially assured pilots and ground staff that the ID card will not be compulsory.
But pilots are angry that the government appears to have reneged on its promise by announcing that all airside staff at airports, some 300,000, would be required carry an ID card in the interests of passenger safety and anti-terrorist work.
The measure was aimed at all airside staff, not just crew. "The minister told us that face to face," said a union spokesman.
Further talks are scheduled with the government. If they break down, Balpa will seek a judicial review of the measure before it considers strike action.
The Home Office confirmed that it was still talking to Balpa. ""We are working closely with the aviation industry and the plan on remains track," said a spokesperson.
He said that GMB, however, was in favour of the national ID card because it tightened hiring procedures and would enable airline and aircraft services operators to relax hiring criteria to break strikes.