True editorial independence often doesn’t exist in these papers. The owners can – and do – interfere with what is published in their publications, which editors and journalists are promoted or fired as well as which political parties the paper supports.

For example, Harold Evans, a former editor at the Sunday Times, made it very clear to the Leveson Inquiry how Rupert Murdoch interfered with the content of the paper. Evans was often rebuked for “not doing what he [Murdoch] wants in political terms,” including when reporting on the economy. Evans recounted how they almost came to “fisticuffs” because he allowed an economist (James Tobin) to publish an article with differing viewpoints to Murdoch in the Sunday Times. According to Evans, Murdoch’s “determination to impose his will” destroyed the “editorial guarantees that he'd given.”

Evans went on to say:

“Mr Murdoch was continually sending for my staff without telling me and telling them what the paper should be. He sent for the elderly and academic Mr Hickey, who went in tremulously, to be told by Mr Murdoch, "Your leaders are too long, too complex. You should be attacking the Russians more."”

David Yelland, a former editor of The Sun – another Murdoch owned paper – admitted in an interview:

"All Murdoch editors, what they do is this: they go on a journey where they end up agreeing with everything Rupert says but you don't admit to yourself that you're being influenced. Most Murdoch editors wake up in the morning, switch on the radio, hear that something has happened and think: what would Rupert think about this? It's like a mantra inside your head, it's like a prism. You look at the world through Rupert's eyes."

During the Leveson inquiry, when asked about this, Murdoch was also reminded he had previously said, “If you want to judge my thinking, look at the Sun." Murdoch admitted that frequent phone calls happened between the editors and him, although as Yelland shows, the influence of Murdoch could also be more subtle, with editors internalising his values and opinions.

Even The Guardian is compromised, although not as much as other national media companies. The Scott Trust Limited, which owns The Guardian, is wholly owned by the company directors who are prohibited from taking any dividends. The Guardian also claims to be guided by a range of progressive values, including the task of maintaining its editorial independence. However, as Nafeez Ahmed points out in Insurge Intelligence, some members of its board are ex-financiers – binding the Guardian into Britain’s murky financial world in a way which may surprise many of its readers.

With six billionaires as majority voting shareholders for most of the UK national newspapers, it is unsurprising that they mostly supported the Conservatives in the last general election. The Conservatives reduced the top tax rate, and want to reduce it further, giving millionaires and billionaires massive tax breaks. Under the current media ownership structure, how much hope is there of genuine progressive agendas to reduce wealth, income and power inequality that also threatens the interests of the billionaires and companies that own the press?

2) Corporate advertising revenue censors the content

The media relies heavily on corporate advertising, often for more than 50% of its revenue. Just how much varies for different media outlets. Peter Oborne, former chief political commentator at The Telegraph, resigned from his job after he was censored from writing about HSBC because it was one of the paper's major corporate advertisers. He wrote in openDemocracy:

“From the start of 2013 onwards stories critical of HSBC were discouraged…Its account, I have been told by an extremely well informed insider, was extremely valuable. HSBC, as one former Telegraph executive told me, is 'the advertiser you literally cannot afford to offend.'”

Oborne went on to say:

“The Telegraph’s recent coverage of HSBC amounts to a form of fraud on its readers. It has been placing what it perceives to be the interests of a major international bank above its duty to bring the news to Telegraph readers. There is only one word to describe this situation: terrible.”

This situation is not exclusive to the Telegraph. As Nafeez Ahmed points out:

“Here’s something you won’t read in the Guardian. During the Treasury Select Committee meeting on 15th February, it emerged that the newspaper that styles itself as the world’s “leading liberal voice” happens to be the biggest recipient of HSBC advertising revenue: bigger even than the Telegraph.”

Media heavily reliant on corporate advertising is compromised as it influences what is and isn’t written about. As David Edwards and David Cromwell of Medialens have written:

“this corporate structure not only trims individual stories, it excludes entire frameworks of understanding. If writing something disagreeable about HSBC or animal rights is problematic, imagine editors consistently presenting corporate domination as a threat to human survival in an age of climate change.”

Noam Chomsky and Edward Herman give many more examples of this here.

How often do we read articles in newspapers critiquing capitalism, let alone corporate capitalism? Just imagine what would happen to a newspaper’s advertising revenue if it consistently critiqued corporate capitalism. Just think what else is excluded from the press because it would seriously challenge corporate advertisers.

3) Privately educated white men dominate the media

There are different studies showing the dominance of a private-school and Oxbridge educated elite at the top of UK journalism, and the trend has been getting worse. The recent Social Mobility and Child Poverty study found out that nearly half of UK national newspaper columnists graduated from Oxford or Cambridge (as opposed to less than 1 per cent of the population) and that 54 per cent of the nation's "top 100 media professionals" attended private schools (compared to around 7 per cent of the population).

This creates an upper middle-class worldview in much of the media – as well as in many other professions – which is divorced from the wants and needs of large parts of the population. As Oxbridge educated journalist, Frank Cottrell Boyce, has written in The Independent:

“Only 25 per cent of the population earns more than £30,000 a year. Most media commentators (including me) do. For people like me, the country basically works. Politics doesn't affect me. Politics, for me, is about how other people are treated. It's easy inside my echo-chamber to believe that I am the norm, or the middle. Easy to forget that there are voices outside.

“To people in my position, austerity can be read as regrettable but pragmatic. But to my friends and family, who live outside the bubble, it's not regrettable, it's terrifying. It's also not pragmatic. The crackpot, gimcrack ideological nature of austerity becomes more apparent the closer you get to the point of delivery.”

Mark Mardell, a privately educated journalist, echoed a similar but tamer view for the BBC:

“It is hardly surprising that Westminster journalists crave the ideologically soft centre. None is on the minimum wage, let alone tax credits, nor are any, to my knowledge, owners of third homes on the Cayman Islands, or running big corporations. They are nearly all university educated and live in London or the South East of England (Yes, all that goes for me, too). There is group-think in the muddled middle, a fear of thinking outside a comfortable box.”

It is not just private and Oxbridge education which dominates the media. Due to the under-representation of Black, Asian and minority ethnic (BAME) journalists, as well as the frequent racist portrayal of BAME people in the media, Media Diversified was set up to try and combat this.

Women are also heavily under-represented, both in journalists employed but also in the amount of coverage received. Research on the UK media by Professor Lis Howell found that between April 2014 and September 2015 the number of male experts interviewed on flagship news programmes outnumbered female experts by 3.16: 1, with ITV News at 10 having 4.9 male experts for every woman. In previous research, Prof Howell also found ten times as many UK male politicians featured on the news as female politicians. Research by Women in Journalism and others in 2012 also found that men dominated news stories in a wide range of ways, such as front page stories being about or written by men around 80 per cent of the time.

Even if they wanted to, these privileged and predominantly white, male, privately educated, Oxbridge graduates often can’t truly understand, let alone accurately represent in the media, the situations and choices faced by most people as they are outside their own life experiences.

How many have strong links with working class communities? How many of these influential journalists have been long-term unemployed, on low incomes, on benefits or tax credits, with long-term health conditions or have faced racism or sexism? How many fall back into repeating ideas to each other within the “echo-chamber” of the privately and/or Oxbridge educated, while falsely believing they are in the “muddled middle”?

4) The political use of supposedly neutral sources

The sources which are used by journalists and the range of debate published within the UK media can show us another way in which the corporate media is deeply compromised. There have been academic studies proving that systemic bias exists in how the media covers events. Three events can be used as examples – the Scottish referendum, the 2008 financial crisis and the second Iraq war.

A team of academics studied the coverage of the Scottish independence referendum between 17 September 2012 and 18 September 2013, looking at 730 hours of evening TV news output broadcast by BBC 1, Reporting Scotland, ITV and Scottish TV (STV), and found them all to be biased against Scottish independence.

(Professor John Robertson summarising his research and the different ways the media was biased against Scottish independence)

As Professor Robertson of the University of the West of Scotland (UWS) has outlined, anti-independence statements were aired over pro-independence statements at a ratio of around 3:2 on most channels. The research also showed a clear tendency to use anti-independence over pro-independence ‘expert’ sources, including from organisations presented as independent and/or impartial despite their linkages to UK government departments with a vested interest in maintaining the union.

After Robertson’s research was published it was stonewalled and mostly unreported by the BBC. The BBC then went above Robertson’s head to his Principal at the UWS to try (unsuccessfully) to discredit the research and colleagues of his were even warned to “stay away” from him! Robertson followed up this research with a one-month intensive study of BBC Scotland’s extended ‘flagship’ politics show, Good Morning Scotland, which found similar bias around the independence campaign.

Paul Mason, former economics editor for the BBC’s Newsnight and economics editor for Channel 4 News, confirmed this bias when he later told his Facebook followers of the BBCs referendum coverage: "Not since Iraq have I seen BBC News working at propaganda strength like this. So glad I'm out of there."

Other studies of the media have found similar results of bias in relation to the financial crisis. Dr Mike Berry, of Cardiff University, authored such a study – The Today programme and the banking crisis (not open access). The table below, from the study, shows the sources featured during the intense six weeks of coverage on the BBC’s Today programme following the collapse of Lehman Brothers in 2008.