It is not uncommon, particularly in the western districts of NSW, for bail to be conditioned upon the accused refraining from consuming alcohol, and requiring an accused to submit to breath testing as required by a police officer.
In the recent decision of Garling J in Lawson v Dunlevy  NSWSC 48 it was held that the second part of the condition, requiring submission to breath-testing, was invalid.
The essence of the decision is that the imposition of the breath test condition did not satisfy any of the purposes for which a bail condition could be imposed, namely: promoting effective law enforcement; the protection and welfare of a particular person or the community; or promoting the treatment or rehabilitation of the accused.
It was not suggested that the condition could be imposed for the purpose of promoting the treatment or rehabilitation of the accused (although there is no reason why in an appropriate case that could not be a relevant purpose). It is also difficult to see (as Garling J found) how that condition could have the purpose of protection and welfare.
However, with great respect to Garling J, the reasoning by which his Honour found it did not have the purpose of promoting law enforcement is unconvincing. This reasoning is in essence based upon the proposition that breaching a bail condition (such as the one prohibiting the consumption of alcohol) is not an offence but simply renders the accused liable to be apprehended and brought back before the courts for redetermination of bail (either by confirming the existing bail, imposing new bails conditions, or dispensing with bail altogether).
While that proposition is undoubtedly correct (leaving aside the offence created for ultimately failing to appear), it takes too narrow a view of "law enforcement", and suggests that "law enforcement" is directed only towards the prevention and detection of criminal offences. It is difficult to see why promoting the observance of bail conditions (and facilitating the detection of their breach) is not also a species of law enforcement. That the legislature has decided that the consequence of breach shall be the redetermination of bail, rather than creating an offence that may be punished in the ordinary way, would seem to be beside the point.
The current review of the Bail Act 1978 can be expected to result in legislative changes that will reverse the effect of this decision.