The finance minister has repeated his pledge that identity cards will not be needed to access devolved services.
Tom McCabe: "No more solid assurance about our approach"
Tom McCabe said he hoped his statement to the Scottish Parliament would end the "unhelpful confusion" which had been generated around the issue.
Green MSP Patrick Harvie said Mr McCabe had avoided answering detailed points on use of a national identity database, which was the major part of the system.
Mr Harvie said the database was a "real threat" to civil liberties.
The finance minister told MSPs that proposals for an identity card scheme were confined to reserved policy areas only.
He said: "I repeat that we are satisfied that its provisions and the powers it would create are for reserved purposes only.
"In terms of our position on the use of ID cards in Scotland, we have been very clear that we do not wish to link them to the provision of devolved services.
"Any change in this position would require an Act of the Scottish Parliament. There can be no more solid assurance about our approach to the scheme."
Mr Harvie, the Scottish Greens' justice spokesman, said a motion agreed by the parliament had called for a statement on the National Identity Register - the database - and its use by devolved institutions.
He said: "None of the serious concerns about the use of the database have been addressed.
"Nothing on function creep, nothing on data sharing, nothing on the presumption of accuracy, which is a huge problem given that much smaller, simpler systems such as NI numbers and driving licences are riddled with inaccuracies.
Green MSP Patrick Harvie is opposed to the cards
"And nothing on the fact that individuals will be required to pay for the privilege of having inaccurate information corrected."
He also said the statement had not said how and in what circumstances devolved institutions would use the new ability to access information on the register.
Mr Harvie said: "We need a clear commitment that no public services will be affected by the information on the database, and we need to know that the most restrictive possible approach will be taken to the whole scheme."
Scottish National Party justice spokesman Stewart Stevenson said Scots would be "paying through the nose to have their privacy invaded, with no tangible benefit".
He said: "Contrary to the minister's statement, Scottish data and our systems will be copied to the national identity database.
"This is completely unacceptable and an infringement of civil liberties."
Ministers suffered a rare Holyrood defeat in February when a Green motion describing Westminster plans for identity cards as an "unacceptable threat to civil liberties" was carried by 52 votes to 47, with 15 Liberal Democrat abstentions.