Galloway set off for the United States on Monday determined to face down allegations that ousted Iraqi president Saddam Hussein awarded him the right to buy oil.
The US Senate Permanent Subcommittee on Investigations last week released documents that it said showed Saddam personally granted Galloway the rights to export 20 million barrels of oil under the now-defunct UN oil-for-food humanitarian programme.
"The committee came to its conclusions without any questions or contact being made with me," Galloway told Reuters on Sunday.
"It is a monstrous abuse of natural justice."
US on trial?
Galloway boarded a flight to Amsterdam early on Monday with onward connections to New York and Washington.
He is due to appear before the committee on Tuesday.
A radical kicked out from the Labour party for his fervent opposition to the Iraq war and attacks on Prime Minister Tony Blair, Galloway said he was looking forward to putting his side of the story across.
Galloway is accused of being
given the right to buy oil
"I am going to put them on trial, the villains of the piece - the US government and those politicians who support it," he said in a telephone interview.
Galloway, who was a vocal critic of UN sanctions against Iraq, met Saddam during visits to Baghdad in the 1990s.
The outspoken Scot was elected in the previously Labour safe east London parliamentary seat of Bethnal Green and Bow in the 5 May election after he narrowly beat the sitting Labour MP.
The victory was due in part to the Muslim vote turning to his Respect party because of discontent in the Islamic community about the war in Iraq.
The 96-page Senate report, initiated to examine fraud in the UN oil-for-food programme, also said Charles Pasqua, the former French interior minister, who is now a French senator, got vouchers for 11 million barrels.
Under the programme Iraq could grant vouchers that could be used to either buy or sell oil to trading companies.
Both Galloway and Pasqua have denied the allegations, which have surfaced earlier, but with less documentation.