Scarlett Johansson, Eva Longoria and Kerry Washington star in election video

Scarlett Johansson, Eva Longoria and Kerry Washington have joined forces in a promotional video criticising Presidential candidate Mitt Romney.

The Hollywood stars have shot a 30-second film, unveiled by liberal action group MoveOn.org, attacking Romney's policies towards women.

In the clip, directed by Rob Reiner, the actresses raise issues such as abortion and rape, and urge viewers to vote for Romney's rival, incumbent President Barack Obama.

Johansson, already an active supporter of Obama's re-election campaign, ends the film with the chilling line, "If you think this election won't affect you and your life, think again."

MoveOn.org's creative director Laura Dawn says, "MoveOn is releasing this ad to help ensure that women voters know just how backward and extreme Mitt Romney is when it comes to issues affecting women."

The election will take place next month.