Liberal Supreme Court Justice Stephen Breyer says he is undecided on whether to quit

The doyen of the US Supreme Court, Stephen Breyer, who has been under pressure from the left to resign while Democrats are able to name his successor, said Thursday he had not decided whether or not to step down.

The 82-year-old liberal judge has spent 27 years on the high court bench.

Refusing to set a timetable, he told CNN his choice would be based on "primarily, of course, health."

"Second, the court," he added.

The nine judges of the top court are appointed for life, which guarantees their independence, but they are chosen by the president and confirmed by the Senate, which gives them a political label.

They settle debates on which the elected representatives of Congress cannot agree, and rule on issues such as abortion and gay marriage.

In an increasingly divided America, their selection has given rise to several acute political crises, with no let-up expected.

Republican Senate leader Mitch McConnell has made it known that he would block any candidate proposed by Democratic President Joe Biden if the Republicans regain control of the Senate in the 2022 midterm elections.

On the left, several voices have been raised to ask Breyer to step aside before that might happen, so as not to repeat the example of Ruth Bader Ginsburg.

The feminist and progressive icon had not retired under Barack Obama, despite poor health.

Her death at 87, just before the 2020 presidential election, offered Donald Trump the chance to appoint a third conservative judge to the top court.

The left now fears that the strong conservative majority of the court (six judges out of nine) will roll back the right to abortion and complicate the hot button topic of gun control, two subjects on its slate for the next year.