The break-up by security forces of a protest camp in the western city of Ramadi, which triggered the resignation of more than 40 MPs, marks the latest stage in a long political struggle by Iraq's Sunni Arab community.
The protesters had accused the Shia-led government of Prime Minister Nouri Maliki of discriminating against the country's Sunni minority, and the resignations were a display of disapproval at the way Mr Maliki is running the country.
Since the fall of the secular, but Sunni-dominated regime of Saddam Hussein in 2003, Iraqi Sunnis have tried many tactics to achieve their goals but without success.
All the rulers of Iraq since the emergence of its modern state in the 1920s came from the Sunni Arab minority, although in general Iraqi Shia and Sunni lived in peace before 2003.
But the balance of power changed after the fall of Saddam Hussein, and while Shia and ethnic Kurds - most of whom are Sunni - became extensively involved in the US-sponsored political process, Sunni Arabs boycotted it. Even those who had not been supporters of Saddam Hussein worried about their future.
Various insurgent groups emerged and started operating in Sunni areas in western, central and northern Iraq.
Al-Qaeda was the most controversial among them. Although many of its members were foreigners who came to Iraq during the chaos that followed the fall of Saddam, they found sanctuary in Sunni areas.
Sunnis soon realised that not taking part in elections was a mistake. The first free election after the invasion brought a government dominated by religious Shia parties.
Sunnis changed course and contested the second election in late 2005. There was a high turnout in Sunni-dominated provinces, and Sunni parties won much greater representation.
Sunnis joined the first government of Nouri Maliki, but the influential posts went to Shia or Kurdish politicians and Sunni complaints of marginalisation continued.
In 2007, while Iraq was sliding towards unprecedented levels of sectarian violence, Sunnis joined other secular and Shia parties and withdrew from Mr Maliki's government in an attempt to bring him down.
But in their areas something different and interesting was taking place. Insurgents who had been fighting the US forces for years turned to fight al-Qaeda instead with significant American backing. Al-Qaeda had alienated Sunnis with its harsh approach and radical interpretation of Islam.
The gradual defeat of al-Qaeda - which turned out not to have been decisive - and the crackdown on Shia militias gave Mr Maliki significant political credibility and Sunnis rejoined his government.
In the election of 2010, and apparently after understanding that they would not dominate power in the country again, almost all Sunni influential parties joined the Iraqiya bloc led by the secular Shia politician Iyad Allawi.
Mr Allawi had been the first prime minister after the fall of Saddam Hussein and Sunnis resented him when he was in the post, especially during the battle of the mainly Sunni city of Fallujah in 2004.
But now he seemed the best Shia politician that they could accept. They wanted him to be prime minster again and they nearly got that.
They did not win the elections outright but Iraqiya emerged as the coalition with the most seats in parliament.
Yet after months of political deadlock, Mr Maliki still managed to form a new coalition government, after getting significant backing from Iran and all the Shia and Kurdish parties.
Sunnis felt they had to join again for better representation, more senior posts, and more say on strategic and security affairs - or so they thought.
Soon after the US withdrawal at the end of 2011, Mr Maliki started a crackdown on senior Sunni Arab politicians, most prominently Vice-President Tariq al-Hashemi, accusing them of supporting terrorism.
Influenced by the wave of street protests that brought down many Arab rulers, Sunnis took to the streets in late 2012.
The main camp for protesters in Ramadi was broken up on 30 December. With parliamentary elections coming up in April, the resignation of the Sunni MPs is unlikely to have a major impact on politics in Iraq or the policies of Mr Maliki.