Musk, Tesla's billionaire owner, agreed a £34.5bn deal in principle to take over the social media giant last month, pledging to improve what he considers to be limitations around free speech on the site and also to remove fake accounts.

In a pre-dawn tweet today (Friday 13 May, a date perhaps not entirely coincidental), Musk said the deal is now on hold “pending details supporting calculation that spam/fake accounts do indeed represent less than 5 per cent of users”.

His tweet linked to a report published earlier this month which said Twitter estimates spam and fake accounts comprise less than 5 per cent of its daily users.

It is unclear why Musk now considers this detail a potential dealbreaker. It is known that the terms of the deal include a $1bn termination fee that Musk would be obliged to pay should he back out of the deal, although it is unclear how such a clause would apply if Musk were able to show that Twitter’s user figures were misleading...