I think this answers your question (source = Google rather than personal knowledge):
https://www.safe.co.uk/buying-guide/lock-cylinders/ts007-kitemark
There are two ways to attain the TS007 3 Star standard:
(1) Replace your existing cylinder with a TS007 3 Star Kitemarked cylinder
The cylinder will clearly show the 3 Star Kitemark logo. It gives the highest level of security available with several layers of protection built in. You don’t need any additional door furniture either. Watch our video on how to replace your cylinder.
(2) Replace your existing cylinder with a TS007 1 Star Kitemarked cylinder, and your door handles with TS007 2 Star Kitemarked handles.
By combining a 1 Star Cylinder with 2 Star handles, you get the same 3 star rating. It will cost a little more and take more time than simply changing the cylinder, but the end result is the same from a security perspective.