This thread has so many generalisations that I don't know where to start.

OK let's try.

Demonstration does not = moral high ground.

Manual work cannot be equated with administration or management although both are equally important.

Do we want the world run by white van man ?
We can't have a world where everyone does aspirational jobs. Not that I'm suggesting that "office based" is aspirational.
I would not agree that all no manual jobs are not hard work. Because there is no muscle involved does not mean it isn't tiring or demanding. Of course working a hard days graft moving s*** from one place to another takes it out of the anatomy but not all physical labour is poorly paid. Ask a plasterer or a plumber.
The vast majority of socialists are happy to become middle class and yet still remain in denial of the system that got them there.
Of course life is not a level playing field and all the whining about it in the world won't change that.

Corbyn's appeal to his targeted audience is so cynical it makes me chuck.

It wasn't about pay, or what was better, but how people in office based jobs have a nasty tendency to view anyone who may work a labour job as lazy for only working shorter shifts etc.

Having done both, I can highly recommend office work for less exhausting, but it can be more stressful I guess (its hard to be stressed about your job when you spent six hours shifting 25kg loads into a hopper).

Well you speak for yourself, I don't hold that view, does anyone?

I've spent 30+ years in an office. In a brief period of a couple of weeks without work, rather than sign on, I did a bit of labouring for a garden company. At the end of the day I got the standard "bet that's the hardest days work you've ever done" line - I just didn't have the heart to tell him that, while it was physically draining, I'd count it as one of the easiest and most relaxing days I'd had, as you could just switch off your brain - you want that gravel moved from there to there? Done. You want it moved back again because you cocked up? No problem, done. I shovel, I get paid - no decisions to make, no responsibility - it was bliss!

I see - so you attach rhetoric as a blanket to cover the views of those based in offices, how very Gusset!

Only if you misread what I said, it was aimed at those who consider they work hard, but dismiss that done by others in more physically demanding roles.