Actress Alyssa Milano's call for a #sexstrike has ignited social media after the #MeToo activist urged women to abstain from sex to protest against a new abortion law in the state of Georgia.

Key points: Georgia passed a law banning abortions once a fetal heartbeat is detected

Georgia passed a law banning abortions once a fetal heartbeat is detected Milano's tweet divided opinion on social media sparking a debate

Milano's tweet divided opinion on social media sparking a debate Amid wide support she was also criticised for suggesting women only have sex for men

"Until women have legal control over our own bodies we just cannot risk pregnancy," tweeted Milano, the former star of "Charmed" and current cast member of "Insatiable," which is filmed in Georgia.

"JOIN ME by not having sex until we get bodily autonomy back."

Milano's tweet divided opinion on social media, sparking a debate that led to the #SexStrike hashtag trending on Twitter in the US this weekend.

Loading

Her tweet came days after Georgia became the fourth state in the US this year to ban abortions once a fetal heartbeat is detected, which can be as early as six weeks, before many women know they are pregnant.

The law is scheduled to come into effect on January 1 next year.

"We need to understand how dire the situation is across the country," Milano said on Saturday.

"It's reminding people that we have control over our own bodies and how we use them."

The actress, who is also a prominent #MeToo activist, noted that women have historically withheld sex to protest or advocate for political reform, citing Iroquois women who refused to have sex in the 1600s as a way to stop unregulated warfare.

Most recently, she noted that Liberian women used a sex strike in 2003 to demand an end to a long-running civil war.

Mixed reactions

Milano received support from fans and fellow actress Bette Midler joined her in also calling for a sex strike with her own tweet.

Loading

But both liberals and conservatives also lampooned her idea, with conservatives praising her for promoting abstinence and liberals saying she was pushing a false narrative that women only have sex as a favour to men.

"I hate the idea that not having sex is a punishment for men but not for women," tweeted feminist author Jessica Valenti. "I like sex! Why should I deprive myself of it?"

"Self-denial and abstinence for some sort of gain is the antithesis of a sexually empowered world," wrote another.

Milano said the criticism didn't bother her and that her tweet was having her desired effect, "which is getting people to talk about the war on women".

Loading

She said she fears one of the laws could eventually be decided by the conservative-leaning US Supreme Court, which Republicans hope will overturn the 1973 Roe vs Wade decision legalising abortion.

"That is absolutely horrifying to me," Milano said. "Anyone who is not completely and totally outraged by this and doesn't see where this is leading, I think is not taking this threat seriously."

Milano said people have to determine for themselves how long the sex strike should last. For her part, she hasn't decided yet how long she will forgo sex.

"I mean I don't know," she said. "I sent a tweet last night, I haven't really thought much past that this morning."

ABC/AP