Sales at Elon Musk’s Tesla have fallen to a three-year low amid the billionaire’s public spat with Donald Trump. The electric carmaker said customer deliveries fell by 13.5pc in the second quarter of the year, a period in which Mr Musk left his role in the White House and publicly fell out with the US president over his tax and spending bill.

He has been humiliated,” the former pal said, adding that the public moves by the two moguls to bury the hatchet has been “purely cosmetic.”