The Home Office has claimed it has slashed the rolling 10-year cost of ID card introduction by nearly £1bn.

In a report to parliament, the Home Office said it will spend £4.74bn compared with an earlier estimated figure of £5.43bn, but admitted that the savings would come from slowing down the rollout.

Other factors affecting the cost included a reduction in the cost of replacing the current passport application system and planning to enrol fingerprint and photograph biometrics through the market.

The move sparked Tory claims that ID card introduction has suffered "a loss of impetus" and that the move would result in an increase in costs in later years.

A more gradual ID card rollout is now planned to those "in sensitive areas of national infrastructure" in 2009 and "young people who want them" in 2010, with a faster rollout in 2012 accompanied by a Home Office admission this will result "in an overall increase in costs".

The Tories have committed to ditching the project if they win the next general election.

Within the new total, set-up costs have reduced to £320 million and operational costs increased to £4.4bn, at 2008/09 prices. The estimate is accompanied by a "health warning" that there are a number of competitive tendering processes, the first of which has only just begun, and assumptions about applications and staff productivity "all of which may well change". Also excluded is the cost to other organisations using ID cards to verify identities.