Cynically mocking the warnings of the Remain campaign, these are the messages posted on the day of the Brexit referendum and seen by many thousands of people as the UK decided its future.

But what voters won’t have known is the posts, which may have influenced the result, came from Vladimir Putin’s so-called ‘troll factory’.

Made to appear to originate in the UK or EU countries, the posts have only now been traced to the secret St Petersburg operation exposed by The Mail on Sunday last week.

A whistleblower, who asked to remain anonymous for fear of Kremlin reprisals, said: ‘We were active on social media, including Twitter, mainly posting on contentious topics obsessing the Brits.’

Voters won’t have known is the posts, which may have influenced the result, came from Vladimir Putin’s so-called ‘troll factory’

On the day of the referendum, one account called @PeterMagLob, pretending to be German, began tweeting up to 20 times an hour in English about the vote.

The Twitter accounts were among more than 2,700 handed over to the US House Intelligence Committee as being linked to the Internet Research Agency, the Kremlin’s troll army, according to CNN.

Using hashtags such as #EUref, #BrexitInOut, #BritainInOut, and #BrexitOrNot, the messages were all pro-Brexit.

One message – mocking the Remain campaign’s warnings of the consequences of leaving the EU – showed a woman next to a broken-down car with the slogan: ‘If you Brexit your car won’t start in the morning.’

Another showed David Cameron with the comment: ‘That’s hilarious! They actually believe the scaremongering c**p we’ve been putting out?’ Damian Collins, chairman of the Digital, Culture, Media and Sport committee has already written to social media giants asking for details of Russian accounts which posted about UK politics.

Next year, a special session of the committee will be held in Washington DC to question Facebook, Twitter and Google on fake news.

One message – mocking the Remain campaign’s warnings of the consequences of leaving the EU – showed a woman next to a broken-down car with the slogan: ‘If you Brexit your car won’t start in the morning’

Last night Mr Collins said: ‘This is the tip of the iceberg. From even the limited research that has been done, it is clear Russian organisations sought to target and influence voters during the Brexit debate.

‘These are early days in understanding the scale of this threat to our democracy, but it is vital that we do.

'That’s why I’ve asked Facebook and Twitter to give full disclosure in UK elections and the Brexit referendum to the DCMS committee inquiry into fake news.’

Twitter declined to comment on specific accounts, but said of the MPs’ request: ‘Twitter recognises that the integrity of the election process itself is integral to the health of a democracy.

'As such, we will continue to support formal investigations by authorities into election interference.’

PROOF BORIS DID MEET 'RUSSIA INTERMEDIARY' The photo show Boris Johnson with Professor Joseph Mifsud, the mysterious Maltese academic suspected by the FBI of being a link between Donald Trump’s campaign and Russia Boris Johnson has been at the centre of more than his fair share of embarrassing photos, but this one is more awkward than most. It shows him with Professor Joseph Mifsud, the mysterious Maltese academic suspected by the FBI of being a link between Donald Trump’s campaign and Russia. Last week, a Foreign Office source said Mr Johnson had ‘never knowingly met this person… or ever heard of him’. But yesterday, after this photo emerged of the pair at a Tory fundraiser last month, the source said: ‘He has his photo taken with countless people he does not know.’ Advertisement

So, who was behind £425,000 donation for Leave adverts?

Scottish Tory Richard Cook, the CRC chairman, was asked on Channel 4 News earlier this year if the Commission knew where the money came from. He replied: ‘Yes’

Theresa May’s partners in government, the Democratic Unionist Party, were last night at the centre of cover-up claims over the source of a mysterious donation to their Brexit campaign.

Before the referendum, shadowy body the Constitutional Research Council (CRC) controversially channelled £425,000 to the DUP.

Though the DUP volunteered the CRC’s name, questions remained over where the organisation sourced such a large sum – seven times more than the party had spent at any previous election.

The DUP, whose crucial votes have propped up Mrs May’s government, have also opposed plans to make forthcoming transparency reforms regarding political donations in the province retrospective.

The CRC and DUP have both refused to reveal the source of the money, and yesterday it was claimed the CRC had been fined £6,000 by the Electoral Commission for stonewalling inquiries.

Sources at the CRC deny acting illegally.

The new claims, published by respected website openDemocracy, suggested the fine was a record amount against an unincorporated association – a structure commonly used by voluntary sports clubs.

Scottish Tory Richard Cook, the CRC chairman, was asked on Channel 4 News earlier this year if the Commission knew where the money came from. He replied: ‘Yes.’

Jeffrey Donaldson, the DUP Brexit campaign manager, says the party did ‘due diligence’ on the matter.

The bulk of the cash – £282,000 – bought adverts pushing Brexit in the Metro newspaper, which is not available in Northern Ireland.

Labour MP Ben Bradshaw said: ‘For the public to have confidence in our electoral system and democracy, the sources of political donations must be declared by law and this kind of behaviour runs a coach and horse through that principle.’

The DUP said: ‘We support donor transparency and look forward to supporting proposals… that recognise the time is now right in Northern Ireland to publish donor details.

‘Given that we have already taken the step of publishing the detail of the Brexit donor, no question arises about donor anonymity in this instance.’

Mr Cook declined to comment.