BAGHDAD (AP) -- Britain announced Wednesday it will withdraw all but a handful of its 4,000 soldiers from Iraq next year, ending a mission that was unpopular at home and failed to curb the rise of Iranian-backed Shiite militias in the south.
The decision comes as the United States is weighing a drawdown in its nearly 150,000-strong force. President-elect Barack Obama has called for withdrawing all combat troops from Iraq by the spring of 2010, shifting responsibility to the Iraqis for the defense of the country against Sunni and Shiite extremists.
The British announcement, which was expected, signals a conclusion to the role of the second biggest troop contributor to the multinational coalition after the United States. More than 45,000 British troops took part in the March 2003 invasion that overthrew Saddam Hussein.
In London, the Defense Ministry said all but a few hundred of the 4,000 soldiers, most of them in the heavily Shiite south, would be gone by June.
The government did not say when the withdrawal would begin. But the Daily Telegraph newspaper of London said it would start in March, when a U.S. unit takes over the British headquarters at the airport in Iraq's second-largest city, Basra.
A U.S. brigade will deploy to the south to train Iraqi soldiers and secure vital supply lines from Kuwait, the newspaper said. The Associated Press requested comment from the U.S. command but received no reply.
The British have not confirmed whether they will now send more soldiers to Afghanistan. Military commanders have warned that British troops are overstretched from commitments in Iraq and Afghanistan, where Britain has some 7,800 soldiers.
Air Chief Marshal Jock Stirrup, the chief of the Defense Staff, said last month that a major withdrawal of Britain's 4,000 troops in Iraq in 2009 won't mean additional forces can immediately be sent to Afghanistan.
In Basra, Gov. Mohammed al-Waili expressed confidence that Iraqi forces could continue to secure the area - the heart of Iraq's vital oil industry.
"Our security forces are fully ready and prepared to fill any vacuum caused by the withdrawal of British soldiers," he told the AP. "We think that the stable security situation will continue after the departure of the British."
British Prime Minister Gordon Brown had expected to make substantial reductions this year but suspended those plans after Iraqi troops launched a major attack against Shiite militias in Basra last March, wresting control of the city from extremists.
The Iraq war has been extremely unpopular in Britain, and the effort to topple Saddam never enjoyed as much support as in the United States. In 2003, several hundred thousand people took to the streets of London to protest the invasion, and the issue shadowed the final years of Tony Blair's premiership.
Even the current foreign secretary, David Miliband, has acknowledged that the war was divisive in both the country and the governing Labour Party.
"Our whole country will breathe a sigh of relief that an end to this illegal war is now in sight," said Nick Clegg, leader of the Liberal Democrats, the third-largest party in Parliament.
With widespread opposition at home, British troops never took as aggressive a posture as American soldiers to the north, in part because of British sensitivities over its image in Iraq as the former colonial power that crushed a bloody uprising in 1920.
Privately, British officers spoke disparagingly of U.S. "cowboy tactics" in suppressing Sunni insurgents in central and northern Iraq and Shiite extremists in Baghdad and south of the capital.
With the British taking a more passive stand, Shiite militias, including the Mahdi Army of anti-U.S. cleric Muqtada al-Sadr, took control of wide areas of Basra and other parts of the south during Britain's stewardship.
Gunmen held sway until Prime Minister Nouri al-Maliki, also a Shiite, ordered Iraqi soldiers and police to regain control of Basra last March. U.S. aircraft and ground troops provided support for the operation.
But Iraqi officers complained bitterly that the British withheld military support. In August, the Times of London reported that British troops stayed out of the fight because of a secret deal with an Iran-backed militia.
The Ministry of Defense denied any deal was struck and said it held back to ensure that the operation was seen as Iraqi-led.
At least 177 British soldiers died in Iraq, compared to at least 4,209 members of the U.S. military mission. The last combat death suffered by British forces in Iraq was March 26.
Although most British troops are in the south, commandos from the elite Special Air Services serve alongside U.S. special operators in the largely secret war against al-Qaida in Iraq. A British general serves as the deputy to the top U.S. commander, Gen. Ray Odierno.
Also Wednesday, Iraq's election commission announced it will launch a petition drive to see if there's enough support for a referendum to decide whether Basra province will become a self-ruled region.
The commission said it would set up 34 centers across Basra where voters can sign the petition asking for a self-rule referendum. The drive begins on Monday and will last until Jan. 14, commission officials said.
Basra lawmaker Wail Abdul-Latif said that at least 10 percent of registered voters must sign the petition in order for a referendum to be scheduled.
If a majority voted in favor in the referendum, Basra would become a self-ruled region with the same powers as the Kurdish self-ruled area in the north. That would give local authorities more control of the province's vast oil wealth.