Sch 22 para 4
In section 6D (arrest), in subsection (1), for the words after “preliminary breath test” substitute or preliminary drug test the constable reasonably suspects that— (a) the proportion of alcohol in the person's breath or blood exceeds the prescribed limit, or (b) the person has a specified controlled drug in his body and the proportion of it in the person's blood or urine exceeds the specified limit for that drug.