Tesla and SpaceX join legal filing against Trump immigrant ban

Tesla Motors and SpaceX, two companies owned by tech industry giant Elon Musk, have added their names to the list of firms which officially opposes Donald Trump's temporary ban on immigrants from seven countries.

An amicus brief was signed by 97 companies on Sunday, including Apple, Facebook and Google, which simply outlines the opposition to the executive order on the basis of harming innovation and economic growth.

The lawsuit brought by Washington state has already succeeded in temporarily stopping President Trump's executive order from coming into effect, and an appeal from the Department of Justice is currently being heard in San Francisco.

Musk's companies were joined by 29 additional signatories to the brief, including HP and Adobe.

The businessman previously defended his presence on Trump's Economic Advisory Council, on the basis that having more moderate contributors would allow the President to be held accountable for his actions.

"Activists should be pushing for more moderates to advise President, not fewer," Musk tweeted on Sunday. "How could having only extremists advise him possibly be good?"

Musk also asserted that the increase in extremism throughout politics could eventually lead to a war.

"Activists should be pushing for more moderates to advise President, not fewer. How could having only extremists advise him possibly be good?"

The Tesla owner has been a strong advocate for issues such as technological advances and climate change, and spoken at length about how Mars will become "critical" for the survival of humanity.