The head of the US Supreme Court has publicly chastised the leader of the Democratic Party in the US Senate for making threatening remarks against two sitting justices as they consider ruling on an abortion related case.

In a highly unusual move, Chief Justice John Roberts released a statement calling the comments not only inappropriate, but “dangerous”.

Democratic Senate Minority Leader, Chuck Schumer, had spoken at a pro-abortion protest outside the Supreme Court on Wednesday, as the Justices mulled over whether to uphold a Louisiana law that requires doctors who perform abortions to have admitting privileges at a nearby hospital.

Senator Schumer named two newly appointed Justices specifically, Neil Gorsuch and Brett Kavanaugh, and warned them that they would “pay the price” and would “not know what hit them” if they were to vote to uphold the modest restrictions on abortion.