I just read that a Senator has a bill which would force parties to count the cost of all their advertising in the three months prior to an election call as an election expense - so sort of what i proposed, although i wouldn't limit it to 3 months prior to an election. My problem with the 3-month limit is how would a party know when an election might come (in a minority situation)? Even our fixed election date legislation isn't really worth the paper it's printed on. My point being that a party could spend a load on ads thinking there won't be an election for maybe a year or what-have-you, then get a nasty surprise and find they just blew half their election spending limit when the writ is dropped much, much earlier than expected.

http://ca.news.yahoo.com/s/capress/090526/national/political_ads