Monday’s independence poll for the Kurdish north is supported by voters but opposed by Turkey, Baghdad and the west, which fear it will deepen instability

Below the Erbil citadel, where empire and insurrection have been fought out over the course of 5,000 years, Kurdish flags stake out the claim to a nascent era – that of a sovereign state.

Banners were gathering rapidly during the week in advance of a referendum on independence in the Kurdish north of Iraq due to take place on Monday. Hours ahead of the ballot, the citadel square and nearby markets were teeming with Kurds draped in nationalistic red, white and green, symbolising the struggle that they believe will deliver them a new nation from the rump of another.

Defying overwhelming opposition outside Kurdistan, large numbers of Kurds see the ballot as a historic step in a decades-long struggle for self determination. They, like their leader, the de facto president of the Kurdish north, Masoud Barzani, have stared down ally and enemy alike, all of whom have warned that the move could lead to the breakup of Iraq and possibly imperil – not advance – their cause.

The fears of the neighbours and high stakes of regional geopolitics matter little to the referendum’s supporters, who, after a slow start, appear to number a sizable majority in Kurdistan, and the result now appears a foregone conclusion.

Many frame their support through a narrow, nationalistic lens of a necessary divorce from the Iraqi central government – and from Arabs themselves. Sectarianism has spiked in Baghdad and Erbil in recent days, with grievances that had been shielded in recent months now on naked display.

“It may take a while to stop this,” said Saleh Harami, a supporter of the referendum from Duhok. “People need to calm this talk down before it’s too late.”

Facebook Twitter Pinterest The Iraqi Kurdish leader Masoud Barzani at a pro-independence rally in Erbil this week. Photograph: Safin Hamed/AFP/Getty Images

In a tea house dwarfed by one of the citadel’s walls, Seif Zarar, 30, an electricity technician said: “The 25th of September means for me the end of chemical attacks, fleeing from our homes, and only receiving 30% of our wages. Even Saddam never stopped paying our wages, despite what he did to us. I have many Arab friends, but what the politicians are doing to the Kurds is very unfair. Let’s untangle this and get on with our lives separately.”

Other Kurds are less conciliatory. “They killed 11 members of my family, including my father” said Zuhair, a senior employee of the Kurdish government, speaking of Saddam Hussein’s regime. “I was one month old at the time. How could I ever look at them as brothers? They hate us and we have nothing in common with them.”

Sitting nearby, Mohammed Hassan, 80, echoed a sentiment that has taken broad hold in the Kurdish north as the referendum draws nearer – that the strident opposition of the region’s friends has been tantamount to a betrayal.

“We were very surprised by this,” he said. “Everyone was. We never thought that the US and Britain would be so hostile.”

Both countries, along with France, the Arab League, and the United Nations have warned that the ballot could have a destabilising effect on an already volatile region. Washington and London remain invested in the unity of post-Saddam Iraq, which has largely been unable to assert itself in the face of regional patrons in the past 14 years. Both Baghdad and Erbil almost fell to the so-called Islamic State terror group in August 2014 – sharply exposing the dysfunction in both governments. The three painful years since have partially restored authority in both capitals and have led both to consolidate their respective power bases.

Haider al-Abadi, the Iraqi prime minister, is poised to take Iraq to an election next year. And being seen as a national leader who lost one third of the country is not something that he, or his backers, find palatable. “How could he campaign on such a thing?” asked a senior supporter of Abadi’s ruling party. “We will never let this happen.”

The fight against Isis, which has nearly been won across Iraq, gave Barzani the impetus to push for independence – his lifelong cause, and a raison d’etre of his father, Mustafa, a founding figure in the Kurdish north, which has won a partial autonomy in the post-Saddam years. It has also steeled Baghdad to push back hard against such a move, which would further complicate revenue and oil-sharing deals and jeopardise the future of the multi-ethnic, oil-rich city of Kirkuk, which is claimed by both Kurds and Arabs, and was contentiously included in the referendum.

Facebook Twitter Pinterest Young Kurds show off their referendum T-shirts at a rally in Shanadar Park, Erbil, Iraq, on 16 September. Photograph: Cengiz Yar Jr

“Kirkuk is the city of Kurds and Turkmens and Mulla Mustafa Barzani had to go to war in 1974,” said Ayad Jibrael, 53, a baker, in reference to a dispute over Kurdish autonomy at the time between Baghdad and Erbil. “People in Erbil have lived together. People in Kurdistan don’t differentiate between Kurds, Turkmens and Arabs. We have lived in peace together since I remember. Now it is our natural right to ask for independent Kurdistan.”

Abdulrazaq Khudur, 60, a Turkmen kebab shop owner, whose family have owned the business since the 1930s, said: “People in Kurdistan struggled with the kingdom of Iraq, the Ba’ath regime and now with this government in Baghdad.

“It is the right time for the referendum now, because the international community and the west now know about Kurdistan, whereas before no one knew how to find it on a map.”

Addressing speculation that Barzani might accede to a last-minute delay, he said only international guarantees with a fixed timeline and agenda could justify such a move. “We can’t have another Sykes-Picot to promise us something and do a different thing next morning,” he says, referring to the secret 1916 deal between the great powers to carve up influence in the region.

Brawa Hajar, 28, said the international condemnation was not a surprise, and could be overcome.

“It is normal to have negative reactions from Turkey, Iran and Baghdad. [It’s the same for] every nation around the world when they first go for independence in the beginning,” he said. “We’ll never give up on Kirkuk at any cost, and I’m ready to pick up a gun to defend Kurdistan against any threat by anyone.”

Beyond the hopes of the Kurdish street, there is broad, and mounting, international concern that the day after the referendum is likely to look very different. “Not in visuals,” said one senior analyst. “But certainly in tangibles.”

London, Washington, and European states say Barzani’s strategy was to create unity, domestic legitimacy and a mandate that forced Baghdad to the negotiating table for two to five years of post-ballot negotiations. A best-case scenario would have been a form of confederalism, or even independence, international observers say.

But including Kirkuk and other areas to the south, which remain disputed between Kurds and Arabs was an “inflammatory” move that forced Baghdad to react with hostility, the observers say. “It was much more in their face. There has been no unity, no logic, no rollout of the plan. This strengthens the hand of the Shia militias. It definitely allows them to put all the blame on the Kurds.”

Additional reporting by Mohammed Rasool