The A to Z of ID cards

U is for U-turn

The ID cards scheme has been notable for the amount of backtracking and 180-degree turns by ministers on early ID card pledges.

Former Home Secretary Charles Clarke had said it would become compulsory to have a card if Labour won the next general election, while ministers now say the cards will never be compulsory for the majority of UK citizens.

Cards were originally planned to be issued to everyone who applied for a passport from 2010 but the government now says that people can choose whether to receive a card with their passport.

Iris scans were initially touted as a biometric that would be stored on the card but were later rejected by the government in a bid to reduce costs - a decision that has led an academic who reviewed the scheme to claim that fingerprint biometrics will "drown in false matches".