US President Joe Biden says he opposes a Supreme Court move to overturn a historic law there that legalised abortion.
In a draft 'opinion' document, written by US Justice Samuel Alito, the court says the landmark Roe v Wade decision in 1973 was "egregiously wrong from the start".
It is unclear if the draft represents the court's final word on the matter, and it has yet to issue an official ruling.
However President Biden says he us ready to act if the court attempts to roll back abortion rights.
In a statement released by The White House, he says: "I believe that a woman's right to choose is fundamental, Roe has been the law of the land for almost 50 years, and basic fairness and the stability of our law demand that it not be overturned."
He says any decision overturning the ruling would raise the stakes for voters in November's mid-term elections.
"If the court does overturn Roe, it will fall on our nation's elected officials at all levels of government to protect a woman's right to choose.
"And it will fall on voters to elect pro-choice officials this November.
"At the federal level, we will need more pro-choice senators and a pro-choice majority in the house to adopt legislation that codifies Roe, which I will work to pass and sign into law."
The statement adds: "We will be ready when any ruling is issued."
Justice Alito's document was first reported by Politico, which said it had been circulated inside the court.
The draft opinion reads: "We hold that Roe and Casey must be overruled", 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.
The US Supreme Court has yet to issue an official ruling in the case, and opinions - 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 leaked document has been met with disappointment by many, including pro-abortion rights' groups and senators.
Planned Parenthood said it "makes clear" its "deepest fears are coming true" and the US has reached a "crisis moment".
Democratic Senator Bernie Sanders called for people to act "now" to "pass legislation that codifies Roe v Wade as the law of the land".
If the report is accurate, the Supreme Court is poised to inflict the greatest restriction of rights in the past fifty years – not just on women but on all Americans.
— Nancy Pelosi (@SpeakerPelosi) May 3, 2022
In a joint statement, Senate Majority Leader Chuck Schumer and House Speaker Nancy Pelosi said if the report is true, the Supreme Court is "poised to inflict the greatest restriction of rights in the past 50 years - not just on women but on all Americans."
"The Republican-appointed justices' reported votes to overturn Roe v Wade would go down as an abomination, one of the worst and most damaging decisions in modern history.
"The party of Lincoln and Eisenhower has now completely devolved into the party of Trump", the joint statement added.
While US Senate Republican Leader Mitch McConnell described the leaking of the report as an "attack on the independence of the Supreme Court".
"By every indication, this was another escalation in the radical left's ongoing campaign to bully and intimidate federal judges and substitute mob rule for the rule of law".
He said: "The disgraceful statements by President Biden, Speaker Pelosi, and Leader Schumer refuse to defend judicial independence and the rule of law and instead play into this toxic spectacle.
"Real leaders should defend the court's independence unconditionally," he added.
Additional reporting: IRN