The aim is to demonstrate that all the various components - Shias, Kurds, and Sunnis - are united in their opposition to the regime of President Saddam Hussein, and yet at the same time are committed to maintaining the territorial integrity of Iraq.
Laith Kubba, a London-based Shia intellectual member of the Iraqi National Congress (INC), told the Independent that the purpose was 'to broaden the participation in the INC process'. He described the meeting as consultative in nature, to prepare the way for another, fuller meeting somewhat short of a conference possibly next month.
He expected all the main groups to be sending representatives, including for the first time some of the avowedly Islamic Tehran-based Shia groups.
He said that a leading Shia opposition figure, Muhammad Baqr al-Hakim, the head of the Supreme Council of the Islamic Revolution in Iraq, would also be sending a representative. Mr Hakim had boycotted the first meeting in June in Vienna of the Iranian National Council, which had set up an 87-member assembly. The Dawa party has also announced it is sending a high-level delegation. Both the Kurdish Democratic Party (KDP) of Masoud Barzani and Jalal Talabani's Patriotic Union of Kurdistan (PUK) will be represented.
The fact that it has taken more than a year and a half since the ending of the Gulf War to bring together the different groups and forces in opposition to President Saddam underlines how divided they are about aims and means.
Not only do they reflect different confessional allegiances (including the small Turkoman community of an estimated 500,000 to a million people). They have different political orientations, such as Communists, dissident Baathist Arab Nationalists, and independent former officers like Hassan al-Naqib based in Damascus. And they are also aligned with different states or powers: Syria, Iran, Saudi Arabia, and the West. It is unclear whether the Saudi-backed Salah Omar Ali Takriti is to be represented.
The Saudis and the Kuwaitis have both established contacts with Mr Hakim's group. But a serious problem within the Iraqi opposition is that the credibility of the Iran-based groups is compromised by being associated and supported by the one country which throughout the past 13 centuries has been the enemy.
Common opposition to President Saddam is not in itself sufficient to unify the different groups. Furthermore, they have different agendas.
The Kurds would be far happier to have some form of separate homeland in Kurdistan. The Shias vary between those who would like to maintain a united Iraq in which their position as the majority group would be reflected in the power structure, to those who believe Shia interests would be best served by some federated arrangement.
The main constraints on President Saddam's writ are territorial and economic, rather than the action of opposition elements outside the country.
The declaration of an air exclusion zone over much of southern Iraq, together with the establishment last year of a Kurdish safe haven, have reduced the area under Saddam Hussein's thumb.
The activities of the Iraqi opposition, however, are mere pinpricks to the thick hide of the regime, according to a leading expert on Iraq, Amitzia Baram. Surveying several key areas of the Iraqi system - Saddam Hussein's family, the army, the Republican Guard - he noted that there had been only slight changes in the past year and a half since the end of the Gulf War.
The family gathered round President Saddam, on whom he traditionally relied for his closest associates, was still one unit, at least in appearance. President Saddam's son Uday had been troublesome, but had no real position of power. Otherwise President Saddam continued to do what he had always done, balancing cousins from his father's side against half-brothers from his mother's side.
The whole system of security and power in Iraq is designed to protect President Saddam and to maintain his regime. The problem of any internal opposition is that for any group to have enough power to topple President Saddam it would have to have a level of organisation and strength that would be easily detected by President's Saddam's many and mutually balancing security arms.
There are two possible explanations for the appearance in the past few weeks of opinions expressed by family members such as Uday at variance with President Saddam's declared policy. Either the President is loosening his grip on centralised power. Or more likely, he is preparing the ground for some shift in policy.