Why would you want to use a blood ketone meter rather than urine ketone testing? Well, ketones need to be dealt with as soon as possible to avoid a potential medical emergency situation. Ketones will not spill over into the urine at first, so blood ketone measurement enables you to detect, and therefore treat, ketones quickly. Have a look at this article by Gary Scheiner.
Meters available in the UK, with ketone test strips on prescription, include:
Your diabetes clinic is unlikely to object to the need for a blood ketone meter. If the GP refuses to provide blood ketone test strips because of their cost, ask the hospital-based diabetes specialist team to write to your GP to request the prescription.
More information about ketones, including the difference between low grade ketosis caused by a low-carb diet and diabetic ketoacidosis (DKA) here.