David Blunkett has come under fire for recruiting people to promote ID cards before MPs have approved them.
Compulsory plans for ID cards have proved controversial
Lib Dem spokesman Mark Oaten branded the government "arrogant" after it emerged the Home Office was advertising for a marketing manager.
The Home Office said more needed to be done "to improve understanding" of the plans amongst the general public.
Mr Oaten said: "I would like to remind the home secretary that ID cards are not universally popular."
He added: "It's typical of this arrogant government to start employing people to promote ID cards before it has even been announced in the Queen's Speech, let alone debated in parliament."
A Home Office spokesman meanwhile said: "We always made clear that development work on the scheme would go on in parallel with the draft Bill, before we ask Parliament, to make the final decision."
Further development work had been recommended by the House of Commons home affairs select committee, the spokesman added.
More to be done?
"The head of marketing is a key role within the programme," he said.
"We need to bring in marketing expertise now to help us with analysing the requirements for research, marketing, communications and stakeholder management.
"The role will take responsibility for positioning and promoting the identity cards scheme to the general public and stakeholders during the passage of the Bill and through to launch.
"Research indicates that whilst there is increased awareness of the proposals for id cards, more needs to be done to improve understanding of the detailed plans amongst the general public.
"We therefore need to start planning now to improve public awareness and understanding in readiness for rollout of the first cards from 2008."
Mr Blunkett told BBC News his department would not be employing people to sell the ID cards physically until Parliament had given its approval.
Fight against terrorism?
Civil rights groups are among those to express concern about the government's plans for ID cards.
The Lib Dems have already said they will oppose legislation aimed at introducing ID cards and the Tories have said the plans are fatally flawed.
Mr Oaten said: "The bill is going to face stiff opposition both in the Commons and the Lords."
He added that the way the Home Office was going about preparing for the introduction of ID cards suggested that "parliamentary scrutiny seems to be an inconvenience rather than a necessity".
Mr Blunkett has argued that ID cards will help prevent identity theft, combat international terrorism, and aid the authorities in combating illegal working and immigration.