Mark Zuckerberg blamed his long-serving COO Sheryl Sandberg for the fallout surrounding the Cambridge Analytica scandal which rocked Facebook earlier this year and sparked consumer fears over whether or not they could trust the company, it has been claimed.

The Wall Street Journal cites several unnamed sources who claim Zuckerberg blamed Sandberg for her handling of the scandal.

Sandberg, who joined Facebook from Google in 2008, was entrusted with heading up the company's Communications strategies.

According to the sources, Zuckerberg did not respond well to how she handled the breach which involved Cambridge Analytica, a firm which helped shape the Trump campaign and has been linked to Brexit, buying the data of 51million Facebook users without them knowing about it.

It took Zuckerberg five days to respond to the scandal when it erupted in March this year.

He and Sandberg issued coordinated statements saying they regretted it but which stopped short of apologizing for it.

Facebook CEO Mark Zuckerberg blamed COO Sheryl Sandberg for the PR disaster which encircled the Cambridge Analytica scandal in March, according to sources, and left her fearing for her job

According to the Journal, Sandberg feared for her job afterwards and told friends she thought Zuckerberg might fire her over it.

In recent months, he has taken on a more combative leadership approach which is reminiscent of how he behaved in the company's infancy, the insiders claim.

The mantra he has returned to, they say, is 'move fast break things'.

'The change in attitude is down to his feelings that Facebook is 'at war' with the media which, the sources say, is who Zuckerberg blames for his scandal-ridden year.

In the last year, Zuckerberg's opinions have driven the co-founders of Facebook-acquired apps including Instagram and What's App out of the company.

There has also been rising speculation over the company's role in the spread of fake news and questions over the integrity of its business after it emerged they were, inadvertently or not, misrepresenting the number of video views to advertisers.

In the last week, it has faced questions over its use of Definers Public Affairs, a conservative opposition-research firm which Facebook hired before Sandberg testified before Senators about the company's practices earlier this year.

Zuckerberg is also at odds with Instagram co-founders Mike Krieger and Kevin Systrom who left Facebook earlier this year after a difference of opinion over where to take the app. There were specific fears over users' privacy and whether or not their location should be available to Facebook

What's App co-founders Jan Koum and Brian Acton also left the company over concerns surrounding privacy

Facebook's stock continues to struggle and is a long way from its July 2018 maximum

Facebook declined to comment on the claims when contacted by DailyMail.com on Monday.

Instead, its spokesperson repeated comments Zuckerberg made on Thursday during a press call where he praised her by saying: 'Overall, Sheryl is doing great work for the company.

'She’s been a very important partner to me and will continue to be. She’s leading a lot of the efforts to improve our systems.

'We’re making a lot of progress, and a lot of that is because of the work that she’s doing.'

In March, Zuckerberg tried to play down the scandal by saying that while he Cambridge Analytica had been able to access the data, the rules which allowed it to were no longer in place.

It was however of little consolation to the 51milion people whose data had already been harvested by the company.