Iraqis demonstrate in front of the Basra provincial headquarters in September in support of the creation of a semiautonomous region in the country’s south. (Nabil al-Jurani/AP)

The historic canals that earned this city its nickname, the Venice of the Middle East, are clogged with trash. In some neighborhoods, the garbage is piled so high it blocks streets.

Residents say the debris is just the most visible sign of decades of neglect by the government. Now, a growing number of citizens are pushing for autonomy for this oil-rich southern province of nearly 3 million people.

The local politicians backing the effort envision a semiautonomous state, not an independent nation. But their campaign presents a new challenge for Prime Minister Haider al-Abadi as he tries to prevent Iraq from splintering in the wake of the Islamic State’s gains last summer in the country’s north.

The effort comes as the region’s borders, drawn up by colonial powers with little consideration for the mix of sects and ethnicities on the ground, are fragmenting. That is testing the strong centralized governments that have dominated the Middle East since the fall of the Ottoman Empire.

Proponents hope the Basra region will gain powers similar to those of Iraqi Kurdistan, a semiautonomous region in Iraq’s north. They have even designed their own flag depicting a pair of hands cradling a drop of oil, underscoring the main grievance here — that Basra sees little benefit from the millions of barrels of oil that it pumps out of its fields.

“Basra only gets neglect and injustice, but at the same time they are stealing our resources,” Assad al-Idani, one of the campaign organizers, said of the central government as he addressed local residents at a Shiite meeting hall recently.

“Basra is the cow and they are taking the milk, but leaving the cow to starve,” he told the crowd in the Hayy al-Ghadir neighborhood as his team gathered signatures for the campaign. “It’s our oil.”

The Iraqi constitution outlines a clear route for a province to become a semiautonomous region.

The move requires a referendum, which must be held if a petition for autonomy wins support from a third of the members of the provincial governing council or gets signatures from 10 percent of the region’s registered voters — around 160,000 in the case of Basra.

More than 100,000 signatures have been collected since the fall, according to Mohammed al-Tai, a member of parliament from Basra who is backing the initiative. But the exact total is unclear, since a variety of groups are collecting names.

Tai argues that more autonomy would enable Basra to provide better services. At the moment, even minor development projects require authorization from the central government, slowing them down and creating opportunities for officials to demand bribes before issuing approvals.

In Basra, multimillion-dollar projects routinely stall or run aground.

Basra residents chant slogans supporting the creation of Basra region during a demonstration in Basra, 340 miles southeast of Baghdad, last September. (Nabil al-Jurani/AP)

The foundation stone for Palm City, a Dubai-style commercial and industrial mega-project planned to include 100,000 housing units, was laid two years ago, but construction is yet to begin.

Imad al-Hassani, a spokesman for the Basra governor, described the delay as a “mystery.”

“There are projects where money has been paid but nothing has been done,” he said. “We are trying to fight the corruption.”

The flagship Sports City stadium and commercial development was slated to be finished before the 2013 Gulf Cup soccer tournament, but it just opened its doors.

Not everyone agrees that autonomy is the answer to the region’s problems. In an interview in his office on a rubbish-strewn street in this port city’s al-Shoula district, Dawai Karim questioned whether decentralizing power would reduce the rampant corruption.

“There are too many thieves,” said Karim, the head of the local governing council. “As long as we have corrupted parties, nothing will change.”

It takes multiple calls to local authorities before trash is collected, he said — they usually do not come unless it is blocking a road. In December, Basra’s governor told the local news media that out of 8,000 municipal workers on the books in the province, only 2,500 actually existed. Others were “ghost workers,” with salaries paid to people using fake names — a common form of corruption in Iraq. The governorate recently signed a deal with a Kuwaiti company to pick up the garbage, but the service has not started.

“Basra should be the best province in Iraq,” Karim said. “It has the ports. It has the oil. But there’s no sewage system, and we can’t even collect the trash.”

It is not the first time Basra has made a bid for autonomy; an effort in 2010 failed to get as far as a referendum. Politicians who supported it complain that then-Prime Minister Nouri al-Maliki, who fiercely defended the central government’s authority, obstructed their attempt. They see their chances as stronger under Abadi, who has said he is in favor of devolving more power to the provinces.

The prime minister believes decentralization “will enhance Iraq’s national unity by giving people greater say on running their day-to-day decisions,” said Rafid Jaboori, spokesman for Abadi.

However, if Basra were to become more autonomous, that would weaken the central government’s control over its resources at a time when the plunge in oil prices has it struggling to balance its books. The government’s budget depends overwhelmingly on crude-oil exports, and Basra produces the largest share of them.

“The scheme could become quite threatening if the Basra federalists press for powers similar to those [Kurdistan] is demanding in oil questions,” said Reidar Visser, an independent Iraq analyst.

But that is exactly what Basra may want. Kurdistan gets 17 percent of the national budget and negotiates its own contracts with oil companies. Wael Abdel Atif, an Iraqi politician who has been pushing for an autonomous region for Basra since 2003, argues that this province should be allowed to award oil contracts itself and be given 10 percent of the national budget.

During a trip to Basra in December, Abadi stressed that becoming a region with greater powers is a constitutional right — but one that needed further discussion.

Supporters of autonomy say they, too, want to proceed with caution.

“It’s not wise to put a date on when this could be achieved,” said Tai, the member of parliament. “There are many people who are against this, many parties against this.”

Still, the issue has the potential to present serious problems for Iraq’s government. Tai said that if a legitimate bid for a referendum is ignored, the campaign could resort to other tactics, such as disrupting Iraq’s oil supply through strikes.

“Even if it means protests and using our strength, we will impose it,” said Sheik Madlool Halfi, a local tribal leader, claiming his tribe has at least 30,000 armed men. “We will consider using them in good time.”

Mustafa Salim contributed to this report.