Maybe you should consider reading some sources:
The criticism isn't just coming from me, or the Tories. What he did was a tragic error, not only in attending, but also what he said.
Behave, I've read a lot of support for Milliband's speech as well as criticism coming from old NuLabour types who can't understand why the party doesn't want Blair 2.0.
Also, economic apartheid is a logical fallacy (appealing to emotion). Not least as apartheid is a race-related term. I have several friends in Hull, Liverpool and Bradford, from the unemployed to doctors. None have complained about cleansing and killings yet.
The literal meaning of apartheid is separateness, I think is entirely appropriate to draw comparisons. If you can afford to live in an affluent Tory area you get preferential treatment from the state and a higher quality of life, if you can't then you suffer from absence of public services, higher crime, generally intolerable life. Pretty much what apartheid was all about.