The newspaper, which is owned by Rupert Murdoch's NewsCorp, emblazoned the headline "BeLEAVE in Britain" across Tuesday's front page, urging its readers to set themselves "free from dictatorial Brussels," arguing that:
"Throughout our 43-year membership of the European Union it has proved increasingly greedy, wasteful, bullying and breathtakingly incompetent in a crisis. Next Thursday, at the ballot box, we can correct this huge and historic mistake."
Despite the paper's unashamed backing for a "Leave" vote though, its Scottish counterpart — The Scottish Sun — has elected to remain neutral; leading some to speculate that the endorsement has more to do with reflecting the views of its readership than influencing them.
Critics have suggested that media mogul Rupert Murdoch's support for Brexit is far more sinister than first meets the eye, with many pointing to an old quote from Anthony Hilton's Evening Standard column, where he said:
"I once asked Rupert Murdoch why he was so opposed to the European Union. 'That's easy,' he replied. 'When I go into Downing Street they do what I say; when I go to Brussels they take no notice.'"
Editor of the online newspaper CommonSpace — Angela Haggerty — told Sputnik:
"It's tricky when the Sun backs a political party or a decision, to know whether it's them influencing it or whether they just bet right. Because the Sun always likes to be on the winning side, and the question is — do they influence the result, or do they just call it right before it happens?"
"I would suspect therefore, that The Sun probably thinks it's going to be a Brexit, which is interesting in itself. But on the other hand, I think there are a lot of people who feel confused by all of the information that's been thrown at them, so if a trusted brand — and it is a trusted brand for a lot of people, they've got a lot of readers — says it's safe to vote for Brexit, then I think it could be a game changer."
The Sun newspaper has a history of backing the winning side in UK elections — the only notable exception being the 2007 Scottish election — and they've been known to brag about their influence, famously claiming, "It's the Sun Wot Won It" after a narrow victory for Margaret Thatcher's Conservative Party in 1992.
Christopher Silver — author of "Demanding Democracy: The Case for a Scottish Media" — told Sputnik that the Sun's endorsement would only serve to polarize the referendum debate further:
"Given Rupert Murdoch's long-term political project — to promote a mistrust of progressive elites — there is nothing surprising about this news.
"Essentially it just embeds the battle lines that have been drawn up for some time. Older voters, who are more likely to be conservative, more likely to read newspapers and more likely feel a strong British identity, are the Leave campaign's base. This aligns very clearly with the Sun's readership and the values the paper has long espoused," Silver told Sputnik.
UK citizens will vote on June 23 in a referendum on the country's EU membership.