Thinking Canadians know that the "first past the post" electoral system is outdated and undemocratic in a multi-party state. The only fair system to replace it with is some form of proportional representation. All politicians know this. Some political parties oppose it because they fear a potential loss of power (disenfranchised voters are not their concern).
The question is what is proportional representation? Is there more than one variation? If so, which version is best and most easily understood by voters?
Pure proportional representation is the most democratic because it reflects exactly what voters want. Briefly, this is how it works: Each voter has one vote, just as now. Voters vote for the party of their choice, not for candidates. The number of seats each party receives is determined by their percentage of the votes cast. Each party has an established list of candidates (with the leader in position one, the others listed however the party chooses). The successful candidates are chosen from the list starting at the top. A simple system easy to understand and implement.
But it has a number of drawbacks, the most important of which is potential political instability. For example, if a party gets an MP for every 100,000 votes it receives, there is a good chance that many splinter parties will receive a few seats. Germany and France, among others, had this system prior to World War II, Italy and Israel still have it now. Anyone who follows international politics closely will know that the Israeli government is extremely unstable because it consists of a coalition made up of many parties that have almost nothing in common. Hence, the lack of progress resolving the Arab-Israeli situation, for example.
In order to resolve the apparent contradiction of fairness and stability, a modified system of proportional representation has developed since World War II which works very well and is easy for the average unsophisticated voter to understand. That system is usually called Mixed Member Proportional Representation, commonly abbreviated to MMP, and is used successfully in many democratic countries.
In a nutshell, here's how it works: each voter has two votes - one for the party of choice, one for a candidate in a riding (the same as now) who does not necessarily have to be from the same party. The seats are allocated on the basis of 50% from the first vote and 50% from the second vote. Essentially this means that voters still have the benefit of a local MP whom they can feel a connection to and to whom they can turn for help in the case of problems with government agencies. At the same time, voters who favour smaller parties (such as the Green Party) will not be disenfranchised as they are now.
The potential drawback of splinter parties causing instability is resolved by establishing a threshold which must be exceeded for party representation. This is usually set at 5% of the total vote and has worked very successfully at keeping extremist and one-issue parties out (for instance in countries like Germany and New Zealand which use this system). The threshold does not apply to candidates who are elected personally by the second ballot (i.e. Elizabeth May would still have been elected, even if the Green Party had not received enough votes to pass the threshold).
There is another variation of proportional representation called the Single Transferable Vote system. I won't explain it here. It's extremely complicated to explain and understand. It's the system proposed here in BC and voted on twice by referendum and turned down twice in 2005 and 2009. It may be democratic and fair, but because of its complexity is not supportable.
The Mixed Member Proportional system is very easy to understand and implement and is fair to all points of view, and above all it's democratic. That's where we need to go - after all, most Canadians favour a democratic system of government, don't we?