Members of the House of Commons held a debate Thursday to mark the 10th anniversary of the British engagement in Iraq.
Caroline Lucas, former leader of the British Green Party, led the debate, saying the anniversary comes as a sobering reminder.
"Iraqis are being hit by almost daily attacks, with tensions growing between the Shiite majority and the minority Sunnis, raising fears of a return to the worst level of sectarian violence," she said during the debate.
She said the British government considered May to be the deadliest month for Iraq since 2008, with more than 1,000 civilians and security officials killed.
"It is a grim understatement to say that the Iraqi people do not have security," she said.
Lawmakers questioned evidence that prompted the British government to enter the U.S.-led conflict. The British government in 2009 ordered an inquiry to examine the 8-year period beginning with the push for war in 2001 to July 2009 when British forces ended their mission in Iraq.
Labor member Glenda Jackson supported assertions the decision in 2003 to join the conflict was flawed. The U.S. government chose to use force in response to what it considered a threat from Iraq's program of weapons of mass destruction.
No such weapons were discovered.
"If any value has come from that disastrous foreign policy, it has to be that we have learned how never, ever to do it again," Jackson said.