Harrison Ford is defending Dr Anthony Fauci following President Trump's threats to fire him after the election with the Hollywood star urging Americans to sack Trump instead.

The 78-year-old actor teamed up with The Lincoln Project political group to narrate an anti-Trump advertisement that was released on the eve of the election.

In the one minute advertisement, Ford hits out at Trump's recent threats to fire Fauci in the wake of the election. 

The Hollywood star lists off Fauci's experience as director of the National Institute of Allergy and Infectious Diseases and his works with previous administrations. 

'He has served the American people tirelessly, honorably and selflessly from Reagan to Bush to Clinton to Bush to Obama, and now, to Trump,' Ford said.

His narration accompanied photos of Fauci working alongside the previous presidents before showing footage of the infectious disease expert putting his head in his hand during one of Trump's White house COVID-19 briefings. 

The ad from the never-Trump conservative group then cuts to footage from Trump's rally in Opa-locka, Florida on Tuesday in which his MAGA supporters can be heard chanting: 'Fire Fauci'. 

'Don't tell anybody but let me wait until a little bit after the election,' Trump told his supporters. 

The ad continues with Ford saying: 'Tomorrow, you can fire only one of them. The choice is yours.'