181,000 migrants who should have left the UK since December 2008 could still be here

Up to 181,000 migrants who should have left the UK since December 2008 could still be here, according to UK Border Agency estimates.

The agency "does not do enough" to check people have left once their visas expire, the National Audit Office said.

The NAO said the agency should set national targets on tackling those who overstay their visas.

Immigration Minister Damian Green said radical reforms were being brought in and abuses would be clamped down upon.

The UK Border Agency is responsible for running the points-based immigration system for non-EU workers.

Since it was introduced in 2008, 182,000 migrants from outside the European Economic Area have been allowed to enter the UK for work - and a further 179,000 already in the UK have been given leave to remain.

Whitehall's spending watchdog, The National Audit Office, said while the system was largely well designed and helped meet immigration aims, it was not yet providing full value for money due to inefficient systems and customer service.