The US Tea Party movement could cause an American recession which would have worldwide consequences, Trade Minister Craig Emerson says.
His assessment comes after Treasurer Wayne Swan made a speech accusing the Republican Party of harbouring "cranks and crazies", as Congress is prevented from resolving its budget problems, known as the "fiscal cliff".
Dr Emerson said the "irrational behaviour of a substantial number of Tea Party members of the Republican Party" needed to be questioned as the Congressional deadline approached.
"By December of this year if something isn't done then ... that could lead to a contraction in the US economy of up to 5 per cent," he told ABC Television on Friday.
"That is a deep recession."
Dr Emerson said this would have global consequences.
"What Wayne was saying is that whatever happens in the elections in November, it is incumbent on the US Congress to get a compromise agreement so that the whole world doesn't follow the United States over a fiscal cliff," he said.
"It is a perfectly sensible thing to say, it is a warning that should be issued, other countries are issuing this warning."
But coalition frontbencher Peter Dutton said the Tea Party was right to raise concerns about US debt levels.
"There's nothing wrong with people saying that we need to curb excessive expenditure," he said.