Elon Musk and Donald Trump's relationship has turned sour in recent days, after the world's richest man donated to the Republican's presidential campaign and joined his cabinet.

White House press secretary Karoline Leavitt doubled down on Republicans’ criticism of the nonpartisan Congressional Budget Office’s scoring of the president’s tax and immigration bill, claiming that the independent agency — which warned that millions could lose health-care access if the measure is signed into law — has been “historically wrong.”