First Past the Post wastes our votes. In the 2015 elections half of us might as well have stayed at home.
Half the votes cast in 2015 didn't help an MP go to Westminster - the highest proportion in a recent election. Representing some 15 million people who did not see their choice reflected in the outcome. This is a similar figure to 2010, when 52.8% of votes didn't elect anyone.
When you include the votes that went to candidates that were already elected, nearly three-quarters of votes were wasted (74.4%, compared to 71.1% in the last General Election); that’s 22 million people who voted yet had numerically no influence on the outcome. We have the ludicrous situation where candidates in safe seats are getting elected with votes to spare, then all the votes for candidates from the same party being wasted as they didn't get enough votes.
In any electoral system, there are a certain number of votes that do not count towards electing a member of parliament – but in First Past the Post this is taken to extremes.