George Galloway said he would be meeting various Iraqi leaders and members of the public during his trip.
The MP for Glasgow Kelvin is angry at the latest pronouncements from the United States over the need for a change of leadership in Iraq.
President George Bush is committed to the removal of Saddam Hussein as president, despite the Iraqi leader's offer to discuss the return of United Nations weapons inspectors.
Mr Galloway told BBC Radio Scotland that he was in Iraq with a number of people from European and Arab countries.
"We are determined that we are going to do everything we can to stop this rush over the cliff," he told BBC Radio Scotland.
He said most of those accompanying him in Iraq thought that their countries would prefer it if the issue could be resolved diplomatically with the return of the inspectors.
He warned against "being plunged into a war with incalculable consequences for Iraq, for the invaders and for the whole region, which will be destabilised in the extreme".
Serious reservations
Mr Galloway has also accused UK Prime Minister Tony Blair of not being honest with the British public over his intentions towards Iraq.
The media had been briefed on one line while Mr Blair was making different remarks to King Abdullah of Jordan, Mr Galloway claimed.
"He has told the King of Jordan that he has very serious reservations about this attack on Iraq.
"He has told the British press that there is almost certainly going to be one and that we will be part of it.
"But he has not told the British Parliament, and therefore the British public, anything at all."
However, Downing Street stressed that no decision had been taken regarding Iraq.
A spokesperson said that there would be nothing to say on the subject until a decision was made - and denied that the prime minister had told any lies.
Mr Galloway has already warned Mr Blair that the government would be split if the UK backed any attack on Iraq.
Iraq has invited the United Nations' chief weapons inspector to Baghdad for talks about resuming arms inspections.
Air strikes
This offer received a cool response from the UK Government, while the United States said the invitation made no difference to its demand for "regime change".
Mr Galloway has been a long-standing critic of the sanctions imposed on Iraq at the end of the 1991 Gulf War, which he has described as "one of the great crimes of the 20th Century".
He has made a number of trips to Iraq, including one trip from London to Baghdad in a double-decker bus aimed at drawing attention to the alleged suffering caused by the embargo.
Last year he visited Baghdad to visited people injured during air strikes.
Earlier this year Mr Galloway again warned that further UK-backed action against Saddam Hussein could have a disastrous effect.