The first part of the 1967 Australian referendum to change the Constitution was the Parliament question, which related to the relative number of members in each house of the Australian Parliament − the so-called "nexus".

[1] The most important effect of the "nexus" in the Australian Constitution is to prevent the dilution of the collective voting power of the Senate, which represents the Australian states equally, in any joint sitting of both houses following a double dissolution election.

The nexus ensures that Senators will always have about one-third of the votes in a joint sitting, and Members of the House of Representatives about two-thirds.

The referendum question asked the public to vote on whether "the number of members of the House of Representatives may be increased without necessarily increasing the number of Senators".

Do you approve the proposed law for the alteration of the Constitution entitled 'An Act to alter the Constitution so that the number of members of the House of Representatives may be increased without necessarily increasing the number of Senators'?