Australia’s federal parliamentarians have never been so thinly spread. Whereas at Federation there were 51,000 Australians per House of Representatives MP, there are now 170,000 Australians per MP. That leaves MPs stretched and voters disengaged.

It is bad enough that there are 170,000 Australians per MP, but it is even worse that rounding the NT’s quota down would lead to 250,000 Northern Territorians for one MP.

The risk of NT representation falling dramatically exposes deeper problems in the distribution of MPs in Australia. Australia’s population has grown dramatically since Federation, but the number of MPs has not kept up – with no more MPs now than there were in the 1980s. This leaves all MPs responsible for ever larger electorates, and makes the under-representation of people in the Northern Territory particularly acute.

The extreme case of the NT also exposes the existing disproportionality in the distribution of MPs among the states and territories. As an original state, Tasmania has always received more MPs than its population would strictly entitle it to – while the smaller territories have been limited to what the quota, strictly applied, gives them. Due to rounding, this can leave the territories either significantly over- or under-represented based on whether they happen to cross a particular population threshold.

A simple way to address both problems would be to increase the size of the House of Representatives. Even a small increase would guarantee the NT’s second seat for the foreseeable future, but a larger increase would make MP allocations less “swingy” and address the problem of under-representation.

We recommend an increase of about 50 percent: to around 223 members of the House of Representatives, and a commensurate increase in senators to 18 per state.

This increase has several benefits:

•  It would increase representation of the territories, with a guaranteed two seats for the Northern Territory and the possibility of three. The ACT would have four seats, an increase of one.
•  For the first time since Federation, it would provide for one vote, one value: every state would have the number of MPs its population entitles it to.
• It would return the number of people per MP to around what it was following the 1984 Hawke Government reforms, allowing for more responsive and locally-focused MPs.
• It would increase the talent pool from which ministers can be drawn. The number of ministers has tripled since 1901, or more than quadrupled if parliamentary secretaries are included, while the parliament has only about doubled in size.
• It would reverse the growing geographical size of rural and regional electorates.

It is also worth considering how territory senators are allocated, given an increase to 18 senators per state would leave the ACT and NT’s two senators each looking even more inappropriate.

We recommend a simple formula: territory senators should be allocated so that they receive senators proportionate to Tasmania’s population and senators. For example, the ACT’s population is 81 percent the size of Tasmania’s population. If Tasmania receives 12 senators (the status quo), then the ACT would receive 10 senators. If Tasmania receives 18, the ACT would receive 14.

This would ensure better representation for the Northern Territory in the Senate as well as the House of Representatives. The NT would go from two senators to six (if senators per state remains at 12) or from two senators to eight (if senators per state increase to 18).

It is also in keeping with the spirit of the Constitution, which provides for smaller polities to receive proportionately more (but not absolutely more) parliamentarians to reflect their vulnerability.

If these changes are not feasible in the short term, there are more limited changes that could help ensure representation for the territories:

• Allocating territory MPs based on Tasmania’s ratio of population to seats, rather than the states’ ratio of population to seats.
• Using the “harmonic mean” to allocate seats instead of the arithmetic mean, as suggested by Antony Green.
• Setting a floor of two for Northern Territory seats, as would be achieved by Senator Malarndirri McCarthy’s bill.