Buy tile drill set from Toolstation, they don't shatter like the
Screwfix one's do. However, they do lose their edge if they are allowed
to overheat, but can be sharpened with a quick touch up on a diamond
wheel. If you need a larger dia hole, then resharpening a normal masonry
drill to a shape similar to the tile drills with the diamond wheel can
be worth while.

Regards
Capitol