Where a police officer has reasonable grounds to suspect a drink driving offence he can require a road side breath test. When such a test is failed, further testing can be required at the police station by way of a further breath test or urine or blood samples.
Officers have to follow a set procedure and if they get it wrong the defendant should be acquitted
It's a defence to the offence of failing to provide a sample if you have a reasonable excuse.
Punishment
The most serious offence carries 6 months imprisionment, compulsory minimum ban of 12 months or 36 months if previous offence up to 10 years before, and a fine of up to £5000. The guidance that the court operates to suggests that penalties for this offence should start at a ban of 24 months rather than the 12 month minimum.
Failing to provide a roadside breath test is a discretionary ban or 4 points, and a fine of up to £1000.
