People vote if there is a key issue and a difference between the parties.
If any party was stupid enough to have in their manifesto explicit cuts to key benefits the recipients would vote for those who will keep them.

Everyone does it. The unions back their strokes, the very rich and big business theirs (or more often both).

Before the election the senior GPs were clearly unhappy about the 50% tax bracket. I wasn't as my salary is nowhere near the levels required to be affected.