A document labelled “Opinion of the Court” shows a majority of the court’s justices earlier this year threw support behind overturning the 1973 case that legalised abortion across the country.

According to the political news organisation Politico – who published the “leaked document” – the draft opinion shows the court voted to strike down the landmark case.

However, it is unclear if the draft represents the court’s final word on the matter.

The Associated Press could not immediately confirm the authenticity of the draft Politico posted, which, if verified, marks a shocking revelation of the high court’s secretive deliberation process, particularly before a case is formally decided.

A Supreme Court spokeswoman said the court had no comment.

The document published by Politico was labelled “1st Draft” of the “Opinion of the Court” and was reportedly in reference to a case challenging Mississippi’s ban on abortion after 15 weeks – a case known as Dobbs v Jackson Women’s Health Organisation.

The Supreme Court has yet to issue a ruling in the case, and opinions — and even justices’ votes — have been known to change during the drafting process. The court is expected to rule on the case before its term is up in late June or early July.

The Supreme Court is poised to strike down the right to abortion in the US, according to a leaked draft of a majority opinion that would shred nearly 50 years of constitutional protections. Photo by Stefani Reynolds via Getty Images

The draft is signed by Justice Samuel Alito, a member of the court’s 6-3 conservative majority, who was appointed by former President George W Bush.

“Roe was egregiously wrong from the start,” the draft opinion states.

“We hold that Roe and Casey must be overruled,” it adds, referencing the 1992 case Planned Parenthood v Casey that affirmed Roe’s finding of a constitutional right to abortion services but allowed states to place some constraints on the practice.

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“It is time to heed the Constitution and return the issue of abortion to the people’s elected representatives.”

The draft opinion in effect states there is no constitutional right to abortion services and would allow individual states to more heavily regulate or outright ban the procedure.

Politico said only that it received “a copy of the draft opinion from a person familiar with the court’s proceedings in the Mississippi case along with other details supporting the authenticity of the document”.

The report came amid a legislative push to restrict abortion in several Republican-led states — Oklahoma being the most recent — even before the court issues its decision. Critics of those measures have said low-income women will disproportionately bear the burden of new restrictions.

The leak jumpstarted the intense political reverberations that the court’s ultimate decision was expected to have in the midterm election year. Already politicians on both sides of the aisle were seizing on the report to fundraise and energise their supporters on either side of the issue.

Until now, the court has allowed states to regulate but not ban abortion before the point of viability, around 24 weeks.

First Minister Nicola Sturgeon tweeted: “The right of women to decide what happens to our own bodies is a human right. And experience tells us that removing the legal right to abortion doesn’t stop abortions happening - it just makes them unsafe and puts the lives of women at much greater risk”

There will be a “great deal of anxiety” over reports relating to a “draft opinion” suggesting the US Supreme Court could overturn abortion rights in America, International Trade Secretary Anne-Marie Trevelyan has said.

She told Sky News: “With leaked documents you never quite know, so let’s wait and see, but I am certainly a woman who believes in choice for women and when the Roe versus Wade ruling came through decades ago now … it’s part of our history that acceptance that actually women should have control of their bodies was something that set a standard for the rest of the world and allowed women to be empowered in this very, very critical way.

“So, we’ll wait and see … whether this is a true document or not, but I think there will be a great deal of anxiety if that seems to be true, and I suppose if it goes back to a state-by-state level, the US will have to deal with that in a different way.”

She added: “Issues of concern are always raised through diplomatic channels whatever they might be, they are done privately often because that can be a most effective way of setting out the view.

“It’s a matter of great concern, I think, to all women in the US if this is a rowing back on a 50-year state of things, but we’ll have to wait and see whether it’s true of not.”

Roe v Wade: ‘Draft opinion’ suggests Supreme Court could overturn abortion rights