Momentum's hugely successful Facebook video The Banker and The Nurse © Momentum/Facebook

Nearly 10m people watched leftwing videos on Facebook that appear to have turbo-charged Jeremy Corbyn’s campaign. The cost to make them was less than £2,000.

At the same time, a campaign by traditional rightwing newspapers seems to have fallen flat with voters, even when the Daily Mail attacked Labour’s leadership over 13 pages for spending “their careers cosying up to those who hate our country”.

The persuasiveness of online media, and the apparent decline in influence in this election of Britain’s newspapers, will be picked over in the aftermath of the shock result.

“Despite the bias within the media, [Mr Corbyn] actually managed to connect,” the Labour supporting film-maker Ken Loach told Sky News. “That’s not only a triumph for him. That’s a triumph against the media presentation of him, which has been extraordinary.”

With the Conservatives spending more than £1m on direct advertising on Facebook and other social media channels to attack Mr Corbyn and target floating voters, Labour played a different game combining online ad spending with a low budget grassroots campaign.

According to Momentum, the activist group that played a key role in Mr Corbyn’s election as Labour leader in 2015, its election videos were watched by nearly 13m unique users on Facebook, including 9.8m in the UK — more than 22 per cent of the site’s British users.

“That our videos have been viewed by nearly a quarter of UK Facebook users in the last week shows how slick, timely content that speaks to the issues people care about can help Labour match the millions the Tories are spending on dark Facebook advertising,” said Emma Rees, Momentum’s national organiser.

The group said its highest performing video online, which features a father explaining to his daughter why she doesn’t get free school meals because he voted for Mrs May, achieved 5.4m views in just two days.

By contrast the Conservatives’ highest performing ad on Facebook — a highlights reel of Mr Corbyn talking about security and terrorism — achieved 6.6m views, but these were paid for and were gained over a longer period of time.

Giles Kenningham, a former director of communications for the Tories, said: “Labour have used Momentum to devastating effect. The Tories do not have an equivalent campaigning group pushing out their message.”

Fuelled by the rapid growth of Facebook and smartphone use since 2015, Labour supporting websites such as The Canary, Evolve Politics and Skwawkbox also did their bit, building up huge audiences online by attacking the Tories and the mainstream media.

“The content discovery mechanisms on Facebook in particular are shaking up the UK’s partisan press landscape,” said the media research company Enders. “Highly opinionated, pro-Labour online publications with no direct print equivalents are reaching larger Facebook audiences . . . than most national news brands.”

This was backed up by research from BuzzFeed that found that the most popular articles shared on Facebook were largely pro-Labour, including endorsements of Mr Corbyn, stories on young voter registration and the NHS.

With turnout among 18 to 24-year-olds rising at the election, it appears support for Labour online transferred to the ballot box. Social media platforms such as Snapchat worked with the UK electoral commission to persuade young people to register to vote.

Mr Corbyn’s campaign team bypassed much of the mainstream press, focusing instead on younger media outlets. He appeared on the cover of music magazines Kerrang and NME and was interviewed by the grime artist JME in a Facebook video viewed 2.5m times.

Meanwhile, the UK’s rightwing newspapers, which looked so powerful following last year’s vote to leave the EU, appear to have been wrong footed by the swell of support for Mr Corbyn.

As polls narrowed in the closing stages of the campaign, newspapers such as The Sun and the Daily Mail stepped up their attacks on Labour.

But Charlie Beckett, of the London School of Economics, said as newspapers battle falling circulations and ageing readerships, their power to influence elections is on the wane.

“This kind of bitter, negative coverage might play well with older readers but it’s very short termist as a business strategy,” Mr Beckett said. “Young people didn’t like it and it may have even galvanised younger support for Labour.”

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