Led by independent Bernie Sanders, who caucuses with the Democrats, the 11 legislators said while they appreciated Biden’s efforts to find a bipartisan deal to lift the debt ceiling, Republicans in Congress were “not acting in good faith”.

“We write to urgently request that you prepare to exercise your authority under the 14th Amendment of the Constitution, which clearly states: ‘the validity of the public debt of the United States … shall not be questioned’,” they wrote Biden, a fellow Democrat.

“Using this authority would allow the United States to continue to pay its bills on time, without delay, preventing a global catastrophe,” they said.

Biden is continuing negotiations with House of Representatives Speaker Kevin McCarthy during his trip to the G7 Summit in Japan this week, ahead of the June 1 date when the US Treasury has said the government could start running out of funds if the debt ceiling is not lifted.

The periodic lifting of the federal government’s borrowing limit allows the government to pay for spending Congress has already authorised.

(Reporting by Jasper Ward, Paul and Susan Heavey; Editing by Doina Chiacu and Leslie Adler.)