Funnily enough, Dave, I didn't actually say anything of the sort. It is avfact, however, that the Labour Party has a natural constituency comprising a very large minority of the population who receive more in benefits (of many kinds) than they pay in taxes. This group of people are always likely to vote for parties that promises to raise tax rates, taxes that they will never have to pay.
In addition, the Labour core vote is heavily concentrated geographically, with many constituencies having very small electorates compared to the average (thank you to the Lib Dems for blocking any reform of this over the past 4 years).
Finally, with our First Past the Post system, this means that Ed Miliband can reasonably expect to win in 2015 with only 35% of the turnout which, as you know very well, is their whole strategy.