It is very unlikely that the change in immigration regulation would effect a post graduate course. If at all, it would make a difference to undergraduate courses (diplomas, certificates etc). Best place to check out is at immigrationboards.com

Here is a reply I got when I contacted a current student from LBS for advice ... I believe Tier 4 is the one that you are worried about.

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On 22 March the UK Border Agency made a statement outlining changes for applicants and students from outside the European Economic Area and Switzerland .
· Students admitted to study at London Business School will be eligible for a Tier 4 visa.
· Dependants of students studying on any of the London Business School programmes will be able to work in the UK , according to the UK Border Agency.
· In terms of what happens after graduation, it has now been confirmed that the Tier 1 Post Study Work route will not accept new applications from April 2012.
· However, based on what we currently know, in country transfers from Tier 4 to Tier 2 (employer sponsored) visas will not be capped. Most companies have a Tier 2 licence.
· London Business School continues to work closely with the UK Border Agency regarding the changes.

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