The former secretary of Wales opposed plans for compulsory UK national identity cards in the 1990s as he saw them as a threat to the union, newly released documents reveal.In government papers just released from 1994, the BBC has reported that ex-Welsh Secretary John Redwood said "any hint" of mandatory ID cards would cause "difficulties with nationalist and devolutionist groups".He said the benefits were "not proven – even to the police and the courts", who were most likely to be "keen" on them.The prime minister at the time, John Major, later shelved the proposals.Conservative Mr Major had previously said the cards were key in the fight against crime.