LONDON - The multi-billion pound plan to introduce national identity cards, one of the world's biggest IT projects, is to be postponed until after the next election, the Conservatives claimed on Wednesday.

The government will start rolling out the controversial ID card scheme for foreign nationals this year and had intended to start introducing them for British citizens from 2010.

However, the Conservatives, citing leaked Home Office documents, said the timescale for issuing the cards, which face fierce political and civil rights opposition, to UK citizens had been put back to 2012.

That would probably defuse the issue of ID cards at the next general election, which Prime Minister Gordon Brown must call by 2010.

Home Office Minister Tony McNulty said the ID card strategy remained in place but added that it would still require parliamentary approval before it became compulsory.

"We always said and will come back to the House (of Commons) when we're ready to in terms of any compulsion," he told BBC TV. "So it's all voluntary at this stage, it remains on schedule but I'm clearly not going to comment on leaked documents."

The Conservatives, who have vowed to scrap ID cards if they win the next election, urged the government to shelve the project.

The biometric cards, which will carry fingerprint, iris and face-recognition technology, are expected to cost 5 billion pounds over the next decade. The procurement process began last August.

The scheme has attracted much criticism ever since it was put forward by former Prime Minister Tony Blair, a vociferous advocate who argued it was crucial to combating terrorism, serious organised crime and illegal immigration.

But campaigners have argued the cards would infringe civil liberties and even some members of Brown's own party say it will be a costly flop. Brown himself has appeared lukewarm in public in his support, suggesting he might be prepared to ditch it.

Its credentials have been further damaged by recent admissions that personal data held by the government on millions of Britons had been mislaid in a series of security blunders.

The scheme, which would see Britons issued with ID cards for the first time since they were abolished after World War Two, will require large amount of personal information to be contained on a single central database.

"We have had so many disasters in recent months on the loss of data," Conservative home affairs spokesman David Davis said.

"The idea of putting all of our information, access to every single part of the government's information about you, and me and everybody else in the country in one place is so dangerous to our individual security, it's something they should shelve."