The US Senate committee which accused MP George Galloway of receiving oil money from Saddam Hussein has accused him of lying under oath.
Mr Galloway gave evidence to a Washington hearing in May, where he ridiculed its claims.
Now the senators claim they have fresh evidence linking the Respect MP and his wife to Iraq's oil-for-food programme.
Mr Galloway said: "I did not lie under oath in front of the senate committee." His wife has previously issued denials.
Mr Galloway told BBC Radio 4's Today programme: "The specific allegation against me is that I lied under oath in front of a senate committee.
"In this case the remedy is clear - they must charge me with perjury and I am ready to fly to the US today, if necessary, to face such a charge because it is simply false."
The committee says it has seen bank records linking Mr Galloway and his wife Dr Amineh Abu-Zayyad with Iraqi government vouchers.
Chairman Norm Coleman said documents it had uncovered were "the smoking gun".
Mr Coleman claimed that Mr Galloway had "been anything but straight" with the committee.
But the Bethnal Green and Bow MP launched an attack on senate investigators.
He said: "They have been cavalier with any idea of process and justice so far, but I am still willing to go to the US and I am still willing to face any charge of perjury before the senate committee."
However, in regards to the claims levelled at his estranged wife, Mr Galloway said he had "absolutely no idea" about her alleged business dealings.
"I am not responsible for my wife," he said.
The MP, who said he was not in a position to answer questions on her behalf, went on: "I am bemused at the news that I see on the front of the newspapers."
Mr Galloway appeared before a US Senate committee on 17 May. The former Labour MP travelled to Washington after senators accused him of receiving credit to buy Iraqi oil.
One of the main allegations raised by the senate sub-committee was that Mr Galloway received oil allocations with the assistance of Fawaz Zureikat.
Mr Zureikat, who was chairman of the Mariam Appeal set up by Mr Galloway to help a four-year-old Iraqi girl with leukaemia, has strongly denied making any arrangements linked to oil sales on behalf of the MP.
BBC Washington correspondent Justin Webb said the development meant the senators' confrontation with Mr Galloway had "reached a new and more serious stage".
Mr Galloway has always denied funds from the sale of Iraqi oil were funnelled through the Mariam Appeal.
In December, Mr Galloway won £150,000 in libel damages from the Daily Telegraph over its separate claims he had received money from Saddam's regime. The paper is currently awaiting the result of its appeal against that ruling.