cmcardle75
LIFE MEMBER
In UK they cannot prosecute on the breath test alone. It is only the reason to take you to a police station and do a blood or urine test in order to prosecute.
Actually, an evidential breath test is far more likely than either urine or blood. However, it is a large calibrated machine at the station, not a little hand held device. Two tests are done, with purges in between and they proceed on the basis of the lower test. However, under certain circumstances (certainly at some point in the past, not sure if it is still allowed), they are/were permitted to extrapolate what the level would have been had you been tested earlier.