George Osborne: Boris Johnson is wrong to say low IQs were to blame for people who struggle to get on

Mr Osborne added that there was “increasing agreement” that it is impossible to achieve “equality of outcome, but you should be able to achieve equality of opportunity wherever you come from.”

The Chancellor told the BBC’s Andrew Marr Show: “I wouldn’t have put it like that, I don’t agree with everything he said.

“What I think there is actually increasingly common agreement, across the political spectrum is that you can’t achieve equality of outcome, but you should be able to achieve equality of opportunity wherever you come from, the best chance, and actually education is the absolutely key to this.”

Ed Balls, Mr Osborne’s Labour shadow, said that Mr Johnson’s suggestion that grammar schools should be revived to enable the brightest “cornflakes” to rise to the top of the packet was an “outdated” view of society.

Also speaking on the Andrew Marr Show he said: “I think it was more back to the eighties than back to the fifties, even Margaret Thatcher did not bring back the grammar schools, but that idea that greed is good and the poor are poor because they are stupid, I think that is a pretty outdated view and I think there are too many of those views around these days in politics."

During the speech to Centre for Policy Studies think tank Mr Johnson suggested that the greed of the "Gordon Gekkos of London" promoted economic growth and should not be demonised.

On Thursday Nick Clegg, the Deputy Prime Minister, said that the comments reveal a “fairly unpleasant, careless elitism” behind the image of Mr Johnson as a “funny and engaging guy”.

Mr Clegg added that Mr Johnson’s comments of the relative IQ of the human “species” amounted to the London Mayor treating people like a “breed of dogs.”