MI5’s chief on Wednesday accused WhatsApp and its parent company Facebook of "handing a gift" of end-to-end encryption to terrorists and paedophiles.

Ken McCallum, the MI5 director general, took the unusual step of singling out WhatsApp’s chief executive for criticism and called for new powers to force social media companies to make available secret messages "in cases of exceptional threat".

In comments to journalists, he also warned that Britain must take ownership of the "toxic" issue of racism and not seek to blame foreign "troll farms" for the vile abuse meted out to England footballers online.

In his annual address assessing the threat to the UK posed by hostile states and terrorists, Mr McCallum said extreme Right-wing terrorism was "sadly here to stay" and raised concerns over the "high prevalence of teenagers" involved in often racist ideologies. 

He said the youngest Right-wing terrorist was just 13 when MI5 opened an investigation into his activities. It is thought he was referring to a teenager convicted in Cornwall, who was 13 when he joined far-Right group Fascist Forge and downloaded a bomb-making manual.

He added that the threat from Right-wing terrorism had "grown and morphed quite substantially over the last five to 10 years". Of 29 late-stage attack plots disrupted over the past four years, 10 were extreme Right-wing.

Mr McCallum said extreme Right-wing terrorism is 'sadly here to stay'

Credit:  Yui Mok/PA

Mr McCallum also said the UK’s response to hostile states "cannot be to hide under our beds or refuse to engage with the world" in combating cyber attacks and assassination attempts on British soil. 

He said there were increasing attempts made by hostile powers "at malign interference – seeking hidden relationships with politicians or other public figures to get them to push another country’s line" and named Russia, China and Iran as the nations posing the greatest threat.

In his speech, Mr McCallum, the youngest ever chief of the domestic intelligence service, said the country was "drifting towards danger" over the refusal of social media companies to allow his agents to access messages sent by terrorist suspects.

He said: "End-to-end encryption, done in the way Facebook is proposing, will hand a gift to the terrorists MI5 has to find and tackle – and a gift to the child abusers our colleagues in the National Crime Agency have to find and tackle."

He said Will Cathcart, the chief executive of WhatsApp, was wrong to call the intelligence agency’s objections to end-to-end encryption "Orwellian", likening it to "video cameras placed in every living room".

Mr McCallum accused Mr Cathcart, the head of the California-based tech giant and one of the most powerful people in the industry, of a "mischaracterisation" and insisted MI5 supported the privacy of social media users. 

He said that where MI5 believed "an individual is plotting grave crimes", such as a bomb attack, then companies such as WhatsApp and Facebook should allow them access to messages providing a legal warrant is produced. 

Mr McCallum added: "UK public opinion is clear – terrorists, paedophiles and serious criminals should not enjoy an absolute right to privacy" and what his organisation was seeking was "front door" access to postings by suspects.

Asked about reports that foreign states and overseas "troll farms" had been behind a racist campaign of social media abuse of England players after the Euro 2020 final defeat to Italy on Sunday, he said: "We don’t currently see the particular bits of state-generated disinformation as being a major slice of the problem.

"I would also voice the thought, maybe at the risk of straying outside my own swim lane, if we want to find ourselves overly looking to blame abroad for this phenomenon of racism, we might miss not owning a portion of a problem that is ours, within our own country."