Those Commonwealth citizens who have a grandparent that was born in the UK may qualify for UK Ancestry status. This is a working category and you do not need a work permit if you qualify for this status.

Criteria
You can qualify if:

-  you are a Commonwealth citizen;

-  you are 17 or over;

-  you have a grandparent who was born in the United Kingdom and Islands;

-  you are able to work and you plan to do so in the United Kingdom; and

-  you can support and accommodate yourself and any dependants adequately without help     from public funds

This category also leads to settlement in the UK. Once you have completed four continuous years stay in this status and still intend to work, you can qualify.