On 31 March 2011 the UK Government issued a ‘statement of intent’ setting out how Tier 4 of the points-based system will operate following the changes to the student visa policy. The first set of changes was introduced on 21 April. The next set of changes have come into effect on 4 July 2011.

The changes to Tier 4 that take effect from 4 July are:
> Restricting work entitlements by only allowing those sponsored by higher education institutions (HEIs) and publicly funded further education colleges to work part-time during term time and full time during vacations.

> Restricting sponsorship of dependants to those of students sponsored by HEIs on post-graduate courses lasting 12 months or longer and of government-sponsored students on courses lasting longer than 6 months.

> Requiring institutions to confirm that any new courses represent genuine academic progression from the previous course studied in the UK.

> A streamlined application process for low risk nationals sponsored by Highly Trusted Sponsors.

Further changes to Tier 4 (General) will come into effect in 2011 and in April 2012.
 
Please see Tier 4 visa application guide for further details.

source:http://www.ukvisas.gov.uk