A total of 1,973,412 people, or 98.7 percent of respondents, backed secession in the poll, which has no legal weight, said Asso Kassem of the pro-independence Movement for a Referendum in Kurdistan, the group that organized the exercise.

Just 19,850 people, or 0.9 percent of respondents, voted against and 4,799 spoiled their questionnaires, he added.

Fellow organiser Shamal Huaizi said the two mainstream Kurdish factions had allowed the informal poll to go ahead in the three provinces of northern Iraq which they still administer, despite their opposition to independence for the forseeable future.

"The Kurdish security services authorised us to carry out this exercise on condition that we not do it inside polling stations," he said.

But he stressed that the poll had been conducted across Kurdish-inhabited districts, including the ethnically divided oil city of Kirkuk and parts of Diyala and Nineveh provinces to which the Kurds also lay claim.

Huaizi dismissed the concerns of the two mainstream faction that any precipitate independence move would spark intervention by Iraq's neighbours, fearful of the impact on their own restive Kurdish minorities.

"We are acting in the interests of the Kurdish people and we will not take into account the views of those who reject its right to self-determination," he said.

He argued that Iraqi Kurds had a legal basis to break away as Britain had forcibly incorporated the then-Kurdish majority Mosul region into Iraq following its capture from Turkey in World War I.

"Kurdistan was forcefully annexed by Iraq in 1924 and, following the collapse of the Iraqi state, the Kurdish people have the right to be consulted about independence, as was the case following the fall of the Soviet Union," he said.

Turkey in particular has expressed determined opposition to Kurdish moves for independence or even wider autonomy, and has secured US promises that there will be no redrawing of Iraq's boundaries.