The Confederation of British Industry has written to home secretary Charles Clarke calling for greater openness about the government's proposals for national ID cards.
The government plans to push legislation for the £3.1bn programme, a key plank of Labour's manifesto, rapidly through Parliament.
The Home Office claims the scheme will combat identity theft, terrorism, illegal working and illegal immigration.
But in a letter to the home secretary, CBI director general Digby Jones warned that the government needed to be clearer about the objectives of the bill.
"If business support is to be maximised, the bill must offer greater clarity and transparency. Without this, it is likely to fail in its objective of making the UK a more secure place to live, work and do business," the CBI said.
Jeremy Beale, head of the CBI's e-business group, said the government needed to flesh out its proposals beyond the current "vague structure".
"They need to fill in some of the detail," he said. "They will have a much better chance of getting the legislation through if they take account of the things we pointed out. They need to make it more transparent, and more delineated in how the data is used."
Despite its reservations about the scheme, the employers group believes that the introduction of ID cards could reduce identity theft, and will allow businesses and government to supply services more efficiently.
The scheme has also been called into question by technology experts, who argue that it is poorly thought out and will do little to prevent identity theft, terrorism and illegal immigration.
Before the election Qinetiq, the former government defence research organisation, criticised the plans as too complex and too expensive.
Neil Fisher, director of security solutions at Qinetiq, said the government should simplify the scheme by dropping plans to verify biometric readings of cardholders online against a central database.
Steve Everhard, chief executive at Multos, which worked on the Hong Kong ID card scheme, has warned that the biometric trials conducted by the Home Office were too small to give a true picture of technology.
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