The Secretary, Department of the Interior has forwarded the following memorandum for advice:

General agreement has been reached by all Commonwealth Departments in a proposal for uniformity in the registration and identification of Commonwealth owned motor vehicles. The existing procedure is not uniform in regard to registration or identification but in two of the States, namely, Victoria and South Australia, it has been suggested by the State Authorities that the existing method of registration, and the marking of Commonwealth owned vehicles, does not prevent a possibility of fraud or of evasion of taxation, and further that the various markings used on Commonwealth vehicles are confusing to the Police and the public.

It is understood that the motor vehicle registration laws of the States require that every motor vehicle used on a public street shall bear a number plate and windscreen label. The proposal for uniformity in registration and identification would provide for the issue of a standard type of number plate and windscreen label in a series of numbers throughout the Commonwealth Departments, and there would be a central registry in this Department to ensure prompt information to a State registration authority wherever a motor vehicle is put into use upon the public streets or withdrawn from Commonwealth Service.

The question has been raised as to whether it would be necessary for any legislation to be introduced to give effect to this proposal, as Military and Air Force Regulations have been made for a similar proposal in respect of Defence Department vehicles. In a memorandum of the 24th February, 1937, No. 43/37, your Department informed this Department as follows:

The legal position appears to be that Commonwealth motor vehicles, other than those used by the Defence Department, are subject to the requirements of State law as to registration.⁽¹⁾

I should be glad if you would favour me with your opinion as to whether any legislation is necessary in order to exempt motor vehicles of Commonwealth Departments from being subject to any requirement of State law as regards the use of number plates and labels provided by the State Authorities on the registration of a motor vehicle.

In the memorandum for advice, reference is made to a memorandum from this Department in which it is stated that Commonwealth motor vehicles, other than those used by the Defence Department, are subject to the requirements of State law as to registration. Postal vehicles have also been exempted from such requirements.

As number plates and labels are ordinarily required by State law as evidence of registration, it follows, in my view, that unless exempted from the relevant provisions of State law, it would be necessary for Commonwealth vehicles to bear number plates and labels.

This exemption can only be effected by Commonwealth or State legislation. It is presumed that any legislation exempting Commonwealth vehicles from the requirements of State law would be brought forward by the Commonwealth. The legislation could take the form of regulations in the case of those Departments the principal functions of which are the subject of a particular Act containing a general regulation making power, as in the case of the Defence Department and Postal Department. In other cases, the matter would, in my opinion, require to be dealt with by a Commonwealth Act.

In Pirrie v. McFarlane (36 C.L.R. 170) it was held that members of the Defence Force of the Commonwealth were not exempt from the State legislation requiring the drivers of motor vehicles to be licensed.

Following upon this decision regulations were made under the Defence Act inconsistent with the State law and, by virtue of section 109 of the Constitution, the State law has, since the making of the regulations, been regarded as inapplicable to members of the Defence Force.⁽²⁾

In a dissenting judgment in West v. the Commissioner of Taxation (NSW) (56 C.L.R. 657), Evatt, J. said that the Commonwealth Parliament could not give a general exemption to its servants from obedience to the directions of State officers as to traffic and speed observances and expressed doubt as to the efficacy of section 109 to support Commonwealth legislation overriding legislation by a State within its constitutional sphere.

The regulations made following the decision in Pirrie and McFarlane have, however, not been challenged and, in the absence of any such challenge and of any general support by the other Judges in West