I always vote, but growing numbers don't, and that's a problem that needs addressing. It won't be addressed as long as 'mandates' continue to be endorsed when they represent ever-dwindling fractions of the electorate. How low is too low a share of the vote for the 'winner' to claim a genuine mandate, in an age when the drift of votes away from the two major parties looks set to continue indefinitely? 35%? 30% 25%. Lower than that? At what point do we admit 'this whole process is a sham' and begin to demand it be changed to something more representative?
Many people actively choose not to vote. That doesn't necessarily signal a disinterest in politics, more a general disgust at the process and the paucity of choice on offer.
I think the current Labour party are a disgrace in many aspects. Ed Miliband is a weasel and is just a less popular version of Cameron in his attitudes towards doing anything that his focus groups say. The rest of the Shadow Cabinet with their promises to out-do the Tories on cracking down on benefits claimants (not benefits fraud but claimants) and other nonsense policies are probably the weakest Shadow Cabinet since the early 1980s. I'll still vote for them though because they're the best of a really bad bunch, it's either that or go sulk and tacitly approve the next government with my inaction.
Even if we get 10% of the electorate voting, that's still a democratic mandate if the other 90% are not voting because of apathy. It's their choice not to vote. They could choose to turn up and vote for a local independent, they could vote for anyone they choose on the ballot paper, they could even spoil the paper by writing some obscenities that only a vote counter will see for a fraction of a second.
edit: That picture of Miliband eating a bacon roll like a bit of a nerd was probably a focus group suggesting that people would vote for him if he publicly ate bacon. He'd be fighting with Cameron for first in the line for a punt to the nuts if a focus group suggested it'd get them the vote of the nut punter. Hmmm... there's a thought...