Details of the UK Government's controversial points-based immigration system are being revealed today.

The system is designed to make it easier for highly-skilled workers to enter the UK - but more difficult for those with fewer or lower skills.

It is similar to schemes used in the US and Australia, where foreigners win points for factors including qualifications, work experience and language skills.

A work visa will only be granted to those who gain a certain number of points.

The exact requirements to win points will be unveiled by Home Secretary Charles Clarke.

Ministers have already said there will be four tiers of immigrants, who will be divided by qualifications, income and other factors.