Washington | Senator Joe Manchin of West Virginia, the most prominent Democratic holdout on President Joe Biden’s $US2.2 trillion ($3.1 trillion) social safety net, climate and tax bill, cast fresh doubt on Monday (Tuesday AEDT) on his party’s plans to speed the measure through the Senate before Christmas, saying he still had grave concerns about how it would affect the economy.

Senator Manchin outlined his scepticism before speaking by telephone about the bill with Mr Biden, a discussion that aides to both later characterised as positive.