The prime minister has split the anti-terrorism and immigration roles at the Home Office, in an admission that the two combined is too much for one minister.

Hazel Blears will add counter-terrorism to her brief of policing and crime reduction, while Des Browne, who replaced Beverley Hughes, will concentrate solely on immigration matters.

The changes come after weeks of pressure from Conservatives over revelations that fraudulent visa claims from Romania and Bulgaria were waived through.

Speaking yesterday, the home secretary defended the government's position.

"If you had the level of unemployment of Germany and France, which is twice... the percentage we have, then of course we would not be offering the work permit system... we would be reducing the number of work permits available," he said.

David Blunkett also confirmed that proposals to introduce ID cards in Britain would be published "in the next four weeks", despite concerns over civil liberties.