Ava DuVernay, Chris Evans, and Alyssa Milano are among a host of stars vowing to lead the fight against Alabama's new abortion ban.

Republican lawmakers in the state passed a bill on Tuesday (14May19), making abortion illegal except when the mother's life is at risk. Under the law doctors could face 99 years in prison for carrying out a termination, even in cases of rape or incest.

Condemning the bill and promising action, the Selma filmmaker tweeted: "Don't move forward after reading this like everything is normal. Don't shake your head at Alabama and then keep going about your day. Realize that this is a warning. It's Alabama and abortion today. It's you and your rights tomorrow. Your silence will not save you. So speak up."

The bill will now be passed to Alabama's anti-abortion governor Kay Ivey for approval, although women's and civil rights groups have vowed to fight the law, claiming it violates the U.S. constitution due to the 1973 Roe v Wade Supreme Court ruling that enshrined women's right to legal abortions.

Referencing the ruling in his own tweet, Captain America star Chris wrote: "This is absolutely unbelievable. If you're not worried about roe v wade, you're not paying attention.This is why voting matters!!"

Republican politicians hope to overturn Roe v Wade as U.S. President Donald Trump has appointed a raft of conservative judges, including two to the Supreme Court.

Activist and actress Alyssa, who has called for women to embark on a 'sex strike' to protest moves to restrict abortion in states like Alabama, Ohio, and Georgia, called for an Equal Rights Amendment to the constitution to protect women from moves to roll back their rights.

Other stars horrified by the potential new law include Janelle Monae, John Cusack, Busy Philipps, and Patton Oswalt.