Executive summary

• The periodic redrawing of electoral boundaries is required by law to maintain electoral divisions of roughly equal enrolment size within a state or territory. Redrawing of boundaries is known as a redistribution.

• There are three provisions which may trigger a redistribution—representation entitlement, malapportioned divisions, or expiration of seven years since previous redistribution.

• During the expected life of the 45th Parliament there could be a redistribution of South Australia brought about by the representation entitlement trigger which determines the number of members of the House of Representatives a state or territory is entitled to in relation to its population. If this happens then South Australia will lose an electoral division.

• A redistribution of the Northern Territory, because of the expiration of seven years’ provision, was started during the last Parliament and is expected to be completed in early 2017. The number of divisions will remain unchanged at two.

• A redistribution of Tasmania, also because of the seven years’ provision, will occur early in the life of this Parliament. This redistribution had been deferred because it was scheduled to fall within 12 months of the deemed expiration of the previous House of Representatives. There will be no change to Tasmania’s entitlement to five divisions.

• Redistributions of Queensland and Victoria will also be held because of the expiration of seven years’ provision. Neither state will have a change to its entitlement of divisions.

• If South Australia does lose a division then the next election may be held for a Parliament reduced to 149 divisions.