WASHINGTON (AP) — President Joe Biden is seriously considering proposals to establish term limits for U.S. Supreme Court justices, and an ethics code that would be enforceable under law amid growing concerns that the justices are not held accountable, according to three people briefed on the plans.

It would mark a major shift for Biden, the former head of the Senate Judiciary Committee, who has long resisted calls to reform the high court, though since taking office he has been increasingly vocal about his belief that the court is abandoning mainstream constitutional interpretation. The details were first reported by The Washington Post.

Any changes would require congressional approval, which would be unlikely in a divided Congress. But with Republican nominee Donald Trump bragging about putting the three justices on the high court who are now part of the conservative majority, Biden's call for major changes could help animate his voters.

Biden is also considering calling for a constitutional amendment that would eliminate the broad immunity for presidents granted by the court in its most recent term, after Donald Trump claimed he was immune from prosecution for his actions on Jan. 6, 2021, when a mob of his supporters violently descended on the U.S. Capitol.

The people were not authorized to speak publicly about proposals that have not been finalized and spoke to The Associated Press on condition of anonymity.

The consideration of such proposals comes in response to growing outrage among Democrats about high court opinions that overturned landmark decisions on abortion rights and federal regulatory powers that had stood for decades. There have also been increasing questions surrounding the ethics of the court after revelations about some of the justices, including that Clarence Thomas had accepted luxury trips from a GOP megadonor.

Biden in an interview with BET on Tuesday predicted "there are probably going to be two more appointments" in the coming four years when justices retire and blamed Trump for nominating three conservative justices who helped overturn Roe v. Wade. "Just imagine if he has two more appointments, what that means," he said.

The Supreme Court did not immediately respond to a request for comment on the proposal.

Biden, speaking in a weekend call with the Congressional Progressive Caucus, talked about the possibility, the people said. Biden often tells voters they need more Democrats in Congress and a Democrat in the White House to counter the impact of the conservative-leaning court, but these proposals would go much further.

"And by the way, I'm going to need your help on the Supreme Court, because I'm about to come out. I don't want to prematurely announce it, but I'm about to come out with a major initiative on limiting the court and what we do and — I've been working with constitutional scholars for the last three months, and I need some help," he said, according to a transcript of the call.

About 2 in 3 Americans say they favor term limits or a mandatory retirement age for Supreme Court justices, according to a 2022 poll from the Associated Press-NORC Center for Public Affairs Research.

According to June survey on the court, confidence remains low: 4 in 10 U.S. adults say they have hardly any confidence in the people running the Supreme Court.

The survey found that 7 in 10 Americans think the high court's justices are more influenced by ideology, while only about 3 in 10 U.S. adults think the justices are more likely to provide an independent check on other branches of government by being fair and impartial.

In November, the court adopted its first code of ethics. The policy, agreed to by all nine justices, does not appear to impose any significant new requirements and leaves compliance entirely to each justice.

Republicans have focused for years on remaking the federal judiciary and Supreme Court. When Sen. Mitch McConnell, R-Ky., was the majority leader, he refused to even meet in 2016 with Obama's pick for the high court — current Attorney General Merrick Garland, a federal judge at that time. The nomination stalled until a Republican president, Trump, took over.

Establishment GOP operatives backed Trump because of his pledge to name as many judges to the bench as possible. Their gamble worked. Trump ended up with three Supreme Court nominees and 54 federal appeals court judges, reshaping the courts for a generation.

Democrats are now finally understanding the power of judges as a voting tool, and Biden has made judicial nominations a priority, appointing a record number of judges for a president at this point in his first term, including some of the most diverse picks yet to the judiciary. Biden often speaks about those accomplishments during his reelection campaign, but Democrats have pushed him to go further.

Trump, in a post on his Truth Social platform, panned the possible Biden move, saying: "The Democrats are attempting to interfere in the Presidential Election, and destroy our Justice System, by attacking their Political Opponent, ME, and our Honorable Supreme Court. We have to fight for our Fair and Independent Courts, and protect our Country."