Many people voted for the liberal party because they have always promised to represent the working class, stimulate the economy, create jobs, promote free market principles and basically protect upper middle class wealth. What they did here was the opposite of all of these things. Some compromises are to be expected, but the liberal party literally traded everything for just their austerity plans, which also don't benefit their voters directly. Those people feel cheated, and lost their trust in the liberal party. Recent polls show almost half of them would vote differently today.

Please note I'm not trying to make a point about the politics themselves, just about the different ways politicians can and will deceive voters even when they can't outright make up facts about the effects of their policies. I didn't vote for either of the two winning parties.