Prime Minister Gordon Brown can wait almost a decade before holding a vote on compulsory identity cards, according to calculations made by the opposition Liberal Democrat party.
That would effectively put the politically difficult decision on ice, with a parliamentary debate on the controversial issue shunted well beyond the next election.
LibDem leader Nick Clegg said delays to the scheme, revealed in leaks last week, had pushed back the day when the government would have to properly address the matter.
"The ID system cannot become fully operational till it is fully compulsory, and that requires additional primary legislation," Clegg, who opposes the cards, told Reuters in a telephone interview.
"Initially (the government) were going to do this in 2010 or 2011. By our latest calculation they probably don't need to do it till 2017 or so."
By then around 40 percent of the population could have already been issued ID cards alongside new passports, on current government plans.
Recent non-committal comments by Brown on whether the cards should become compulsory for all have raised speculation the prime minister is growing cool over the issue.
Conservative Leader David Cameron has written to Brown asking for clarification on compulsion.
But the LibDem calculations suggest Brown has plenty of time to come up with an answer -- with a vote possibly two or three elections away.
The government had originally wanted the cards to be compulsory from the start.
But in a concession ahead of the passing of the Identity Cards Act in 2006 it agreed that they would at first be voluntary.
Compulsion would be introduced at a later stage, and only with new legislation.
Under present plans, British citizens will be put on the new National Identity Register database and issued with an ID card containing an electronic image of their photo and fingerprints when they apply for a passport.
