The foreign secretary has claimed on Twitter that allegations Vote Leave broke the law during the EU referendum are "utterly ludicrous": but his cabinet colleagues seem rather more reticent over the issue.
His statement came after Brexit activist Shahmir Sanni told Channel 4 News that the official Brexit campaign overspent. These allegations were denied in a lengthy blog post by its former chief Dominic Cummings.
Other ministers, however, were more reticent than Johnson when asked about the claims on Sunday. Brexit secretary David Davis told the Andrew Marr Show: "It’s really a matter if there’s any truth in it at all for the Electoral Commission to investigate. That’s for them, not a minister to decide."
The health secretary Jeremy Hunt told ITV's Peston on Sunday: "I know Stephen Parkinson... there are two sides to these stories. In terms of what did or didn't happen in the referendum campaign, it is properly a matter for the Electoral Commission."
Sanni has also said the former Vote Leave manager and current political secretary to Theresa May, Stephen Parkinson, outed him as gay in a statement on the dispute, released on Cummings' website.
Parkinson, for his part, has told Pink News: "It would be surprising if Shahmir, Mr Wylie, or those advising them thought I would be able to defend myself against those allegations without revealing my relationship with Shahmir. Sadly, the allegations they have chosen to make are so serious that I have been compelled to do so."
Sanni told the Observer that a donation of £625,000 that Vote Leave ostensibly made to an independent referendum campaign organisation called BeLeave was directed to a digital services firm called AggregateIQ, which was in turn linked to the controversial data firm Cambridge Analytica, currently facing allegations around political campaigning and the harvesting of data from Facebook.
Facebook has today taken out newspaper adverts apologising over the data breach.
Questions have been asked about the donation for years now: BuzzFeed News first reported on the matter in August 2016, and there have subsequently been two Electoral Commission investigations which cleared Vote Leave: A third investigation is still live.
It was not, Sanni claimed, a genuine donation, which mean that Vote Leave went over its campaign spending limit of £7 million. He said he had reported the matter to the Electoral Commission last week.
The former Vote Leave chief Dominic Cummings responded by saying there was no evidence for the claims, his blog on the subject concluding: "You’ll see some of this play out in the papers and on TV over the next few days. But at the end of it we’ll still be leaving the EU, [Cambridge Analytica] will still be charlatans, and the media still (mostly) won’t explain data and (digital) marketing well."