President Joe Biden is proposing sweeping changes for the US Supreme Court he says are needed to rein in a conservative-led court that’s being weaponised to undermine established civil rights principles and protections.

Biden says he will work with Congress to enact reforms, including term limits and a binding code of conduct, but opposition from Republicans in Congress means the proposals have little chance.

“We need these reforms to restore trust in the court,” Biden said on Monday in a speech marking the 60th anniversary of the Civil Rights Act of 1964 at the presidential library of former President Lyndon B Johnson in Austin, Texas.

Biden called on Congress to pass rules that would require the justices to disclose gifts, refrain from public political activity and recuse themselves from cases in which they or their spouses have conflicts of interest.

He also urged the adoption of an 18-year term limit for the justices, who currently serve life tenures.

“I believe the best structure is the 18-year term limit. That would ensure that the country does not have what it has now – an extreme court … that has been weaponised by those seeking to carry out an extreme agenda for decades to come,” Biden said.

Most OECD countries either have term limits or a mandatory retirement age for judges serving on their top court.

Earlier in his presidency, Biden convened a commission to study Supreme Court changes. He has appointed one of the nine justices, liberal Ketanji Brown Jackson.

He also proposed eliminating broad presidential immunity recognised in a July Supreme Court ruling involving former President Donald Trump, warning that the ruling set a dangerous precedent that could see grave abuses in the future.

The top congressional Republican, House of Representatives Speaker Mike Johnson, called Biden’s proposals an effort to “delegitimise the court”.

“This dangerous gambit of the Biden-Harris administration is dead on arrival in the House,” Johnson said.

The Republican National Committee called the proposals part of a scheme to pack the Supreme Court with “far-left, radical judges”.

Biden said he would figure out a way to get the reforms passed.

Since the court in 2020 reached a 6-3 conservative majority, cemented with Trump’s three appointees, it has moved US law rightward.

In its immunity ruling, the court decided that Trump, in a federal criminal case involving his efforts to reverse his 2020 election loss, cannot be prosecuted for actions that were within his constitutional powers as president.

The court has ended its recognition of a constitutional right to abortion, expanded gun rights, and rejected race-conscious collegiate admissions, as well as blocking Biden’s agenda on immigration, student loans, COVID vaccine mandates and climate change.

Supreme Court justices have no binding ethics code. Disclosure laws require them to report outside income and certain gifts, though food and other “personal hospitality” are generally exempted.

Legislation would be required to impose term limits and an ethics code, and it is unlikely to pass Congress, with Democrats controlling the Senate and Republicans the House.