Whilst this may be satire, the suggestion of collaboration between Peter Mandelson and George Osborne is not so far-fetched according to Peter Oborne:

‘And what next, if the Yes side win? Mr Cameron has let it be known that he will step down shortly after the referendum. If he keeps his promise — and his wife Samantha will make certain he does — Mandelson will be there to guide his trusted buddy George Osborne to replace him as PM.
Of course, it was Mandelson who orchestrated Tony Blair walking into 10 Downing Street more than 18 years ago. As they say in Brussels: ‘Plus ça change, plus c’est la même chose.’ (‘The more things change, the more they stay the same.’)
What a turnaround! Who would have guessed that Peter Mandelson, who betrayed George Osborne so mercilessly seven summers ago in Corfu, would end up joining forces with him to install him as the next Tory Prime Minister?’ http://www.dailymail.co.uk/debate/article-3287203...

Interestingly, polling conducted by YouGov last August found that across a series of indicators Jeremy Corbyn's support came from lower income groups, and that there was a slightly greater % of working class supporters than in the general population.

'Mr Corbyn’s supporters also tended to have working class and lower middle class occupations compared to the stronger upper middle class support for some other candidates.

65 per cent of Ms Kendall’s supporters were in the upper middle class group, compared to just 48 per cent for Ms Cooper’s, 40 per cent for Mr Burnham’s, and only 36 per cent for Mr Corbyn’s.'
http://www.independent.co.uk/news/uk/politics/jer...

John Mann has clearly been successful in his intention to sow the notion of Corbyn supporters being well-heeled, out of touch 'champagne socialists' but is not borne out by the polling. However, as he is an ultra-Blairite, I think the reasons for John Mann's peculiar suggestion are pretty obvious.

Isn't the real differentiation from Labour which is, in the public's mind, seen as the party of higher taxes?

George Osborne seems to have adopted the Republican strategy of 'Two Santa Clauses' combined with David Stockman's 'Starving the beast' of government. Like Republican presidents, he is running up the deficit and the debt with the twin fold aim of justifying privatisation/public service cuts and of making it impossible for an incoming government to do anything but clean up the mess. Meanwhile, all but the super-rich are getting wealthier, with cuts to real wages of 30% for the vast majority of the population.

Where is the rebalancing of the economy... let alone deficit reduction? Where is the demand and the conditions for industry to invest? George Osborne is not a Conservative. He is the henchman of US corporations.