President Joe Biden has warned that same-sex marriage could be at risk if the US Supreme Court overturns Roe v. Wade.

The landmark decision is what guarantees access to abortion in the United States and has been in effect since the 1970s, with Planned Parenthood v. Casey upholding the right in 1992.

However, the Court appears to be poised to overturn the decision, according to a leaked draft opinion obtained by Politico on 2 May.

“We hold that Roe and Casey must be overruled,” the document’s author, Justice Samuel A. Alito Jr., states in the draft. “The Constitution makes no reference to abortion, and no such right is implicitly protected by any constitutional provision, including the one on which the defenders of Roe and Casey now chiefly rely – the Due Process Clause of the Fourteenth Amendment.

“That provision has been held to guarantee some rights that are not mentioned in the Constitution, but any such right must be ‘deeply rooted in this Nation’s history and tradition’ and ‘implicit in the concept of ordered liberty’. The right to abortion does not fall within this category.”

Speaking on 11 May at a Democratic National Committee fundraiser in Chicago, Biden expressed concern that other landmark cases could be struck down if Roe v. Wade is overturned.

“It’s not just the brutality of taking away a woman’s right to her body … but it also, if you read the opinion … basically says there’s no such thing as the right to privacy,” he said, according to CNN.

“If that holds … mark my words: They are going to go after the Supreme Court decision on same-sex marriage.”

Although Biden, a devout Catholic, has previously said he personally opposes abortion, he has also stated that his views should not be imposed on the rest of society.

Senate Democrats recently failed in their efforts to advance the Women’s Health Protection Act, which would have preserved nationwide access to abortion.

“As we go forward, you’re going to hear me talking more about what we’ve done and what they’re trying to do,” Biden also said.

The decision on Roe v. Wade, which is not expected to be finalised for another month or so, would mean that abortion rights would be determined by individual states.

Although its final form could change, legislatures in 22 states would likely ban or substantially restrict access to abortion if Roe v. Wade is overturned in the way the draft opinion proposes – a move that would disproportionately affect those who cannot afford to travel for the procedure.

Republican-appointed justices Clarence Thomas, Neil Gorsuch, Brett Kavanaugh and Amy Coney Barrett reportedly voted with Alito, according to a source who spoke to the aforementioned outlet.

Stephen Breyer, Sonia Sotomayor and Elena Kagan, the three Democratic-appointed justices, are apparently working on one or more dissents, with the George W Bush- appointed Chief Justice John Roberts’ position remaining unclear at this time.