The rift between US President Donald Trump and his former adviser Elon Musk has erupted into the open, with each trading insults after the tech billionaire criticised Trump’s tax and budget legislation. The two billionaires escalated the feud, lobbing barbs at one another on the social media sites they each own.

The rift between the two began with Trump saying he was “disappointed” with Musk’s criticisms of his administration’s centrepiece tax and spending bill. Musk then accused that the Trump’s ‘One Big and Beautiful Bill’ as an irresponsible addition to the US national debt. The 1,038-page bill proposes tax cuts to changes to social benefits programs.