Ever since he emerged as a serious contender for the Labour leadership Jeremy Corbyn was subjected to unprecedented vilification by the UK’s dominant Conservative-supporting, pro-Brexit press.

Some of the country’s highest-paid columnists and commentators succeeded in delivering a master class in the character assassination of a British politician.

Steps can be taken to challenge the agenda-setting impact of national newspapers, but that requires the news media at large to have the courage the flag up the heightened politicisation of UK newspapers.

The 24-hour news cycle, and the explosion in social media, have combined to extend the reach of the kind of hostile coverage which was meted out to Corbyn and which constantly repeated the claims of the tabloid press that he was the terrorists’ friend and a security risk.

Whatever one’s views on Corbyn’s past activism, or the company he kept, his demonisation has been intense, concentrated into a four-year period from his leadership campaign in the summer of 2015 through to the lead-up to the general elections of both 2017 and 2019.

Journalists were able to draw on a treasure trove of stories and photographs dating back for 30 years or more.

The challenge for the Tory commentariat’s elite was to find ways to project fear and alarm from faded press clippings from the 1980s and 1990s, and especially images of a much younger looking Corbyn.

Their aim was to exploit his links with leaders of Sinn Fein, and then, in the wake of the Manchester Arena and London Bridge terrorist attacks, his past associations with Jihadists.

Corbyn’s failings in dealing with the Labour Party’s disarray over complaints of antisemitism opened a new avenue of attack.

The now familiar story lines had to be continually reworked, but any study of the journalists’ output underlines their ingenuity and ability to recycle the same material.

Instead of being just supporters, newspapers such as the Sun, Daily Mail, Daily Express and Daily Telegraph have now become campaigners and propagandists for the Conservative Party.

Their front pages are blatant party promotion, although as late as the 1990s most newspapers kept their political endorsements to an editorial column on an inside page.

Press politicisation could be countered by broadcasters, starting perhaps with the introduction of a system of health warnings.

When controversial front pages are reproduced on screen in television press reviews, there should be a notification of a newspaper’s political allegiance, a reminder, for example, that its readers were urged to support Leave in the 2016 EU Referendum or vote for Boris Johnson in the 2019 election.

Television and radio presenters rarely indicate the political background of media guests taking part in press reviews and political discussions.

Columnists and commentators with regular by-lines in Conservative, pro-Brexit papers are often introduced neutrally as “authors” or “historians”.

Radio and television programmes are failing in their responsibilities, misleading the public by giving the impression their guests are somehow independent writers or observers.

Presenters should be far more transparent about the political hinterland of their interviewees, not least, for example, if they were a mainstay of what became a production line of anti-Corbyn tirades.

My fear is that broadcasters will continue to shy away from clarity for fear of losing guests and antagonising still further already hostile newspapers.

Captions: Sun, 12.12.2020; Daily Express, 4.12.2020; Mail on Sunday, 8.12.2020.