THERESA May will today warn an international online terror summit about the rise of the Extreme Right in “weaponising” the Internet.

Attending the event in Paris alongside other world leaders and social media companies, the Prime Minister will call for greater global co-operation to defeat the spread of hatred online, saying countries “need to confront the rise of the Far Right online”.

Her message coincides with the release of new Home Office analysis, which reveals the existence of a white nationalist and neo-Nazi discussion forum - not named for “operational reasons” – that has seen more than 12 million posts in response to almost 1m individual threads.

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The forum has amassed more than 800,000 visits in just one month, 10 per cent of which appear to have originated in this country.

In the past three years in the UK, the number of police investigations into Extreme Right terrorism has been steadily rising, leading MI5 to join the police in combating the threat in 2018. As of 31 December last year, there were 28 individuals in prison for extreme right-wing terrorism offences.

The UK Government insists it is vigilant in its approach to Extremist Right groups and keeps proscribed groups under continuous review, including National Action, banned in December 2016, and Scottish Dawn and NS131, recognised as National Action aliases and banned in September 2017.

Today’s summit, hosted by French President Emmanuel Macron and co-chaired by Jacinda Ardern, the New Zealand premier, has been prompted by the Christchurch mosque attacks in March, which killed 51 people and were livestreamed on Facebook.

It will focus international efforts on stopping social media being used to organise and promote terrorism; attendees are expected to sign up to a joint pledge, called the “Christchurch Call To Action”, to eliminate terrorist and violent extremist content online.

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Monitoring group Tell MAMA identified an almost 600 per cent spike in recorded anti-Muslim hate crimes in the week following the Christchurch attack.

Speaking ahead of the summit, Mrs May said: “The sickening attacks on Muslim worshippers in Christchurch shocked the world. That 1.5m copies of the video had to be removed by Facebook - and could still be found on Youtube for as long as eight hours after it was first posted - is a stark reminder that we need to do more both to remove this content, and stop it going online in the first place.”

The PM said that while there had been significant progress on this issue since the terror attacks on the UK in 2017, the livestreaming of the Christchurch attacks exposed gaps in the international community’s response and the need to keep pace with rapidly changing technological developments.

“My message to governments and internet companies in Paris will be that we must work together and harness our combined technical abilities to stop any sharing of hateful content of this kind.”

Mrs May will also call for countries to take forward a shared, international approach to regulation, and follow the lead set by the UK’s Online Harms White Paper, which would create a legal duty of care on internet companies for the first time.

The PM will add: “All of us here recognise the tremendous potential of technology as a force for good in the world. I profoundly believe in the internet as a place for creativity and new ideas.

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“We have seen what can be achieved when we work together. Collectively, we have the knowledge and expertise to find solutions. Let us be ambitious and steadfast in our determination to ensure that this technology, which can do so much good, isn’t weaponised by those who wish to inflict pain and suffering.”

Examples of social media company progress as set out in their own transparency reporting are:

*Google announced that 81.4 per cent of 7.8m videos removed in Q3 2018 were flagged using automated technology, of which 74.5 per cent had no views at the time of takedown;

*Facebook announced between January and September 2018 that it had taken action on 14.3m pieces of content and

*Twitter announced in May 2019 that it suspended 166,153 accounts between July and December 2018 for promoting terrorism, a 19 per cent drop from the 205,156 accounts suspended in the previous six months while some 91 per cent of accounts promoting terrorism content were proactively suspended by its own internal technology, the majority of which happened before their first tweet.