By Deborah Haynes, foreign affairs editor
Nigel Farage claimed “Russian collusion” when it appeared that a number of signatories to a parliamentary petition calling for the government to stop Brexit came from outside the UK.
It is unclear whether the former UKIP leader genuinely believes this or was simply conveniently drawing on an issue – Kremlin interference in Western democracies – many observers suspect played a part in the Brexit referendum that he and fellow Brexiteers such as Arron Banks won.
Either way, Mr Farage’s remark on his Twitter account is a reminder of the threat to democracy posed by hostile states that use websites and social media platforms such as Twitter and Facebook as a weapon, by exploiting existing divisions in democratic societies.
It is a profoundly serious challenge and one that Theresa May and her government do not appear in public at least to be giving much thought to, particularly in the context of Brexit.
I am not saying that President Vladimir Putin secured the Brexit vote.
It was 17.4 million living, breathing British people – not Russian cyber bots – who ticked the box marked ‘leave’ when asked what they thought about Britain and the European Union.
But there is evidence to suggest that Moscow at the very least deliberately meddled in the public debate leading up to the vote, helping to promote the arguments for Brexit over social media as well as via pro-Kremlin media outlets such as RT and Sputnik.
This fits in with a pattern of Russian hybrid warfare that US intelligence agencies say was also used during the 2016 US presidential elections, with the focus on promoting Donald Trump, and has also been deployed against other Western allies such as the Netherlands.
I am unaware of any empirical research that demonstrates what – if any – impact malign messages that are disseminated over Twitter and Facebook by a foreign state can have in terms of influencing public opinion towards a certain way of thinking and voting.
But the British government when talking about Brexit rightly attaches huge importance to the “will of the people” as expressed by the 52% majority that voted to leave the EU.
So ministers have a duty to ensure this will is not being improperly influenced by external forces that seek to do Britain – or the European Union – harm.
When there are questions about whether outside elements are helping to promote Brexit or – as Mr Farage has suggested – to prevent Brexit from happening by bolstering signatures on the online petition to revoke Article 50, government should be doing all it can to find the truth.
An independent inquiry could have been set up, similar to the investigation into suspected Russian interference in US democracy in 2016 headed by special counsel Robert Mueller that has just concluded.
Instead, in the UK the issue is skirted around with a hollow line repeated by ministers that they have seen “no evidence” of Russia successfully interfering with the Brexit vote.
I am sure that is the case, but it does not answer the question definitively.
The parliamentary Intelligence and Security Committee is investigating Russian activity against the UK.
In addition, the National Crime Agency (NCA), a kind of British version of the Federal Bureau of Investigations (FBI) in the United States, is looking into allegations of criminal offences by Mr Banks and his unofficial Leave.EU campaign in the Brexit referendum.
One of the suspicions is that Mr Banks was “not the true source” of some £8m in funding to Leave.EU – thought to be the biggest single political donation in British history.
He has rejected any allegations of wrong-doing and said the investigation was motivated by political considerations.
Neither investigation by the intelligence committee nor the NCA is set to release findings anytime soon, meaning that if anything untoward is uncovered it will be too late.
And whichever way you sit on Brexit, it should be of concern if a foreign government is pushing a certain agenda in the UK for its own self-interest.
Sky Views is a series of comment pieces by Sky News editors and correspondents, published every morning.
Previously on Sky Views: Adam Boulton – UK marches deeper into Brexit mess created by Cameron and May
Sky Views: UK has a duty to investigate potential Russian interference – Sky News