The US Supreme Court has taken the dramatic step of overturning the landmark 1973 Roe v Wade ruling that recognised a woman’s constitutional right to an abortion and legalised it across the country, handing a momentous victory to Republicans and religious conservatives who want to limit or ban the procedure.

The court, in a 6-3 ruling powered by its conservative majority, upheld a Republican-backed Mississippi law that bans abortion after 15 weeks. 

The vote was 5-4 to overturn Roe, with Chief Justice John Roberts writing separately to say he would have upheld the Mississippi law but not taken the additional step of erasing the precedent altogether.

The justices held that the Roe v Wade decision that allowed abortions performed before a fetus would be viable outside the womb – between 24 and 28 weeks of pregnancy – was wrongly decided because the US constitution makes no specific mention of abortion rights.

A draft version of the ruling indicating the court was likely to overturn Roe was leaked in May, igniting a political firestorm.

Mississippi’s law had been blocked by lower courts as a violation of Supreme Court precedent on abortion rights. .

By erasing abortion as a constitutional right, the ruling restores the ability of states to pass laws prohibiting it. 

Twenty-six states are seen as either certain or likely now to ban abortion.

Mississippi is among 13 US states already with so-called trigger laws designed to ban abortion if Roe v Wade were to be overturned.

Abortion is likely to remain legal in most Democratic-led states. 

More than a dozen states currently have laws protecting abortion rights.

Numerous Republican-led states have passed various abortion restrictions in defiance of the Roe precedent in recent years.

Before the Roe decision, many states banned abortion, leaving women who wanted to terminate a pregnancy with few options.

As a result of Friday’s ruling, women with unwanted pregnancies in large swathes of the US may face the choice of travelling to another state where the procedure remains legal and available, buying abortion pills online or having a potentially dangerous illegal abortion.

Roe v Wade recognised that the right to personal privacy under the US constitution protects a woman’s ability to terminate her pregnancy. 

The Supreme Court in a 1992 ruling called Planned Parenthood of Southeastern Pennsylvania v Casey reaffirmed abortion rights and prohibited laws imposing an “undue burden” on abortion access.