A federal judge has blocked Georgia's controversial abortion ban

A US federal judge has blocked Georgia's controversial ban on abortions from going ahead next year.

Rallies in May called for the protection of the United States' abortion laws after extreme anti-abortion laws passed in Alabama, Georgia, and Missouri. Source: AAP

A US federal court on Tuesday blocked the state of Georgia from implementing a restrictive abortion law whose passage earlier this year sparked an outcry, particularly from Hollywood.

The law, passed in early May by the legislature of the southern state, which is popular as a shooting location for movies and television series, would prohibit abortions as soon as the heartbeat of the fetus is detectable.

People participate in a pro-abortion rights rally in New York's Foley Square in May. Source: AAP

That occurs around the sixth week of pregnancy, when many women do not yet know they are pregnant. The law was to come into effect on 1 January of next year.

Judge Steve Jones of the Northern District of Georgia federal court stayed the law's implementation, saying it contradicts standing US Supreme Court's precedent allowing women the right to abort a fetus before it becomes viable, around the 24th week of pregnancy.

After the Georgia law's passage, several entertainment giants including Disney, Netflix and Warner Studios threatened to cut ties with the state if the measure came into effect.

Actress Alyssa Milano even called for women to boycott sex until the law was repealed.

Abortion opponents are stepping up their efforts to get a case on the procedure before the Supreme Court, in hopes that new conservative justices appointed by President Donald Trump will hand down a ruling tightening the procedure's availability.

Georgia's restrictive law was similar to others adopted by conservative states in the southern and Midwestern US in an attempt to curtail access to the procedure.

Abortion supporters, including Planned Parenthood Southeast president and CEO Staci Fox (left) with American Civil Liberties' Union Atty Sean Young. Source: Atlanta Journal-Constitution

Courts have already struck down several, including those passed by Missouri, Arkansas, Kentucky and Mississippi.

"We won't stop fighting until we defeat all efforts to block access," said Talcott Camp of the American Civil Liberties Union, one of several groups that sued over the law.