Boris Johnson was today facing fresh calls to sack Dominic Cumming's controversial new aide who previously claimed that black people are mentally inferior.

Andrew Sabisky, a self-described 'super-forecaster', answered Number 10's call for 'weirdos and misfits' but has prompted fury with his extreme views.

In 2014, he wrote on Mr Cummings's website that to stop unplanned pregnancies there should be legal enforcement of contraception.

He wrote: 'One way to get around the problems of unplanned pregnancies creating a permanent underclass would be to legally enforce universal uptake of long-term contraception at the onset of puberty. Vaccination laws give it a precedent, I would argue.'

On another blog post discussing female genital mutilation, he claimed: 'It is still unclear to what extent FGM represents a serious risk to young girls, raised in the UK, of certain minority group origins. Much of the hue and cry looks more like a moral panic.'

Andrew Sabisky answered Dominic Cummings's call for 'weirdos and misfits' to take jobs in Number 10

And in another post being circulated on social media, Mr Sabisky claimed black people had lower IQs than white people.

In the article, entitled 'Disabilities by race' he said: 'If the mean black American IQ is (best estimate based on a century's worth of data) around 85, as compared to a mean white American IQ of 100, then if IQ is normally distributed, you will see a far greater percentage of blacks than whites in the range of IQs 75 or below, at which point we are close to the typical boundary for mild mental retardation.'

He added that this was the reason there was a higher rate of black students with an 'intellectual disability'.

His position at the heart of government has sparked such fury in Westminster that ministers are prepared to boycott meetings with Mr Sabisky and stonewall all communication.

They will also demand the Prime Minister overrules his top aide and sacks Mr Sabisky - setting the stage Mr Cummings's first major slap down since he began ruling the roost in Downing Street.

Ministers will demand the Prime Minister overrules his top aide and sacks Mr Sabisky - setting the stage Mr Cummings's first major slap down since he began ruling the roost in Downing Street

The self-described likened women's sport to the Paralympics as well as found to have advocated extreme positions to enforce teenage contraception

'How f***ing dumb is this 'super-forecaster,' a source hitting out at the new hiring told Buzzfeed.

Another asked why officials had not trawled through Mr Sabisky's background to check for anything which could cause the government embarrassment.

The Cambridge graduate, who is a government contractor rather than a fully-fledged SpAd, has deleted several tweets, including one dismissing female Labour politicians Yvette Cooper, Angela Rayner and Rebecca Long Bailey as 'dim'.

In another tweet, Mr Sabisky said: 'I am always straight up in saying that women's sport is more comparable to the Paralympics than it is to men's.'

Boris Johnson's first cabinet meeting following his reshuffle on Thursday which saw the resignation of Sajid Javid

Since his appointment, Cambridge graduate Mr Sabisky has deleted several tweets, including one dismissing female Labour politicians Yvette Cooper, Angela Rayner and Rebecca Long Bailey as 'dim'

Downing Street tonight declined to comment on the reports of a Cabinet revolt.

Mr Cummings, the architect of the Vote Leave campaign in 2016, has imprinted his style as a political maverick on Whitehall since becoming Mr Johnson's right-hand man in July.

But special advisers are becoming increasingly disgruntled at how he treats them - before Thursday's reshuffle he joked that not all of them would be in the next day's meeting.

Mr Cummings is also believed to have masterminded the resignation of Sajid Javid as chancellor by making his political survival conditional on sacking his entire team of advisers - which had been locked in a briefing war with Number 10.

Downing Street's chief strategist has also caused concern in Labour's ranks.

Leadership frontrunner Sir Keir Starmer today warned against the growing reach of the unelected political appointee.

He told Sky's Sophy Ridge: We see the same old divisions in the Tory party and Dominic Cummings is just getting more and more power.

'I know Boris Johnson doesn't much like coming to Parliament, he does at least come for PMQs, I think we're going to have to have DCQs for Dominic Cummings before too long because he is actually holding all the power and how do we hold him accountable?'