PERTH
* By-election triggered by May resignation of Labor's Tim Hammond who retired so that he could spend more time with his young family.
* Held by Hammond with a 3.3 per cent margin.
* Perth is based on the central part of the West Australian capital.
* Labor candidate Patrick Gorman, former Kevin Rudd staffer and WA Labor secretary, is expected to win.
* Fifteen candidates have nominated, but no Liberal candidate standing
* Key issues: education, transport, health, WA's GST share.
