It seems certain that changes to the Electoral Act will occur when the Coalition takes over control of both houses of the Commonwealth Parliament – but what? For over a fortnight now Crikey subscribers have been debating the voting system, speculating that full preferential voting in federal elections leads to a higher informal vote and asking if bringing in optional preferential voting would be an acceptable compromise for those influential zealots in the Government who have long advocated voluntary voting.

While this has been going on, the Parliament’s Joint Standing Committee on Electoral Matters is conducting its inquiry into the conduct of the 2004 election. These inquiries happen after every poll, but with speculation over the future of the voting system closer attention than usual will be paid to its report. The air has been thick with facts and figures. We may as well leave this debate until the Committee hands down its findings, but not before giving the poll wonks a great whacking lot of info to keep them going.

It’s been observed that the informal vote in some electorates is considerably more than the number of ballots needed to swing marginal seats. How should this be considered in the debate? Here’s a guide to it, all kindly crunched by a subscriber, a list of the highest and lowest informal votes by state and division at the last election. Full details of the seats and the results are available at the Australian Electoral Commission site and the Parliamentary Library’s summary of the election here .

Highest Informal Vote 2004 (By State)

State Seat Informal vote Margin

VI C Gellibrand 6.19 15.0 ALP
SA Port Adelaide 7.23 12.9 ALP
NSW Reid 11.44 12.8 ALP
TAS Lyons 4.24 3.7 ALP
NT Lingari 5.00 7.7 ALP
QLD Oxley 7.16 9.7 ALP
WA Fremantle 6.98 7.8 ALP
ACT Fraser 3.73 13.3 ALP

Highest Informal Vote 2004 (Nationwide)

State Seat Informal vote Margin

NSW Reid 11.44 12.8 ALP
NSW Greenway 11.10 0.6 Lib
NSW Chifley 10.44 13.0 ALP
NSW Blaxland 10.06 12.9 ALP
NSW Prospect 9.16 7.1 ALP
NSW Fowler 9.14 21.4 ALP
NSW Watson 8.93 15.1 ALP
NSW Werriwa 8.07 9.3 ALP
NSW Parramatta 8.01 0.8 ALP
NSW Kingsford-Smith 7.94 9.0 ALP

Lowest Informal Vote 2004 (By State)

State Seat Informal vote Margin

VI C Higgins/Bendigo 2.84 8.8 Lib/1.0 ALP
SA Adelaide 4.27 1.3 ALP
NSW New England 2.99 21.0 Ind
TAS Denison 3.29 13.3 ALP
NT Solomon 4.01 2.8 CLP
QLD Ryan 3.93 10.4 Lib
WA Curtin 3.39 14.6 Lib
ACT Canberra 3.58 9.6 ALP

Lowest Informal Vote 2004 (Nationwide)

State Seat Informal vote Margin

VIC Bendigo 2.84 1.0 ALP
VIC Higgins 2.84 8.8 Lib
VIC Kooyong 2.87 9.8 Lib
VIC Deakin 2.87 5.0 Lib
NSW New England 2.99 21.0 Ind
VIC Ballarat 3.08 2.2 ALP
TAS Denison 3.29 13.3 ALP
WA Curtin 3.39 14.6 Lib
TAS Franklin 3.57 7.6 ALP
ACT Canberra 3.58 9.6 ALP