France, March 4 -- In a change to immigration rules announced on Tuesday, the UK will also cease granting work visas to Afghan nationals.

Home SecretaryShabana Mahmood said the ban - the first of its kind - was designed to close a back-door route to claiming asylum.

"Britain will always provide refuge to people fleeing war and persecution, but our visa system must not be abused," she said in a statement.

"That is why I am taking the unprecedented decision to refuse visas for those nationals seeking to exploit our generosity."

The changes are the centre-left government's latest effort to harden its immigration and asylum rules as its rivals on the right use the issue to rally support.

UK toughens asylum rules to discourage migration S...