UK citizens are unlikely to be made to get an ID card for "several years" because a voluntary scheme needs time to "run in", a minister has said.
Identity cards are opposed by the Tories and Lib Dems
But Home Office minister Liam Byrne insisted the government remained enthusiastic about compulsory ID cards.
Gordon Brown last week appeared to have cooled on compulsory ID cards after describing them as just an "option".
But Mr Byrne said the PM was reflecting the fact MPs would have to pass new legislation for cards to be compulsory.
Asked on BBC radio 4's Today if ministers would be drawing up such legislation this year Mr Byrne said: "I don't think we will do that this year because a voluntary scheme will take several years to run in."
The voluntary scheme refers to the fact that identity cards will be issued from 2009 to anyone getting, or renewing, a British passport - albeit with an opt-out until 2010.
That voluntary scheme was a compromise deal struck to overcome Parliamentary opposition to identity cards.
The then prime minister Tony Blair promised legislation after the next election to make it compulsory for all Britons to get - although not to have to carry - a card.
The Conservatives and Liberal Democrats both oppose the cards and say they would scrap them if they got into power.
But Mr Brown last week prompted talk of a rethink after a series of comments including telling an interviewer "there is no compulsion for British citizens".
Mr Byrne insisted that the government remained as enthusiastic as ever about the cards - which in the past he has said he believes will become a British "institution".
He said: "What we will see this year is the introduction of compulsory ID cards for foreign nationals who want to come and stay in Britain.
"By Christmas, we will be issuing those ID cards to foreign nationals.
"Of course that is a great contrast to the Conservative position who said that they would support the issue of compulsory ID cards to foreign nationals when the UK Borders Act was going through the House, then they cancelled their support."
Mr Byrne said ID cards would start being issued for British citizens by 2009, but added: "If we want to make ID cards compulsory for British citizens, we need another Act of Parliament.
"But the UK Borders Act does now give us the power to introduce ID cards for foreign nationals and obviously that makes it much easier for us to prevent illegal immigration."
After Mr Brown's comments last week Keith Vaz, chair of the Commons home affairs committee, said ID cards for foreign nationals were effectively being used as a pilot for compulsory cards for UK citizens.
Former Home Secretary David Blunkett, who introduced the initial identity card bill, said the scheme would not work unless everyone had to have a card.
"In my opinion, without it being mandatory, there is little point in doing it," he added.