Iraq's Shia Prime Minister Nouri al-Maliki should reform laws seen as unjustly marginalizing the country's Sunni Muslims or mass protests could spiral out of control, a top Sunni leader said.
Thousands have taken to the streets  in Sunni stronghold provinces for three weeks of daily protests, posing the sternest test yet for Maliki's fragile government composed of Shias, Sunnis and ethnic Kurds.
Osama al-Nujaifi, parliament speaker and the most senior elected Sunni figure, said Maliki should pass a draft amnesty law to free detainees jailed on terrorism charges and modify laws that many Sunnis say are used to target them unfairly.
Protesters also want to end a campaign against members of Saddam Hussein's outlawed Baath party that Sunnis fear is used to harass their leaders and sideline them from politics.
"They say they want justice and they want to be treated as citizens of the same class ... and if these demands which they present are not met, certainly they will call for ousting the government," Nujaifi told Reuters.
"We are afraid protest leaders and representatives will lose control of demonstrations after a while if they don't convince them that our political partners will change their policies."
The latest protests erupted after security forces arrested the bodyguards of the Sunni finance minister on terrorism charges, a move seen by many Sunnis as a provocation.
Nujaifi belongs to the more moderate wing of the Sunni-backed Iraqiya block in parliament, but Sunni ranks are split, with more radical leaders making increasingly tough demands.
Hardline Sunni Islamists and clerics are calling for Maliki's removal and even the establishment of an autonomous Sunni-dominated region bordering Syria, similar to the country's autonomous Kurdistan enclave in the north.
The peaceful mass protests are compounding fears of a sectarian confrontation  in Iraq which, along with the conflict in neighbouring Syria, would deepen a regional confrontation between Shia Iran and Sunni Arab Gulf states.
Some Iraqi Sunni leaders view the war beween mostly Sunni rebels in Syria and President Bashar al-Assad, an ally of Iran, as an opportunity to strengthen their own position should Assad fall and a Sunni government come to power.
A year after the last U.S. troops left Iraq, tension between Shias and Sunnis is still raw. Thousands were killed in several years of sectarian violence that began shortly after the U.S.-led invasion of 2003 to oust Sunni strongman Saddam.
Whatever the motive of the protests, Sunni discontent is real. Since Saddam's fall, many feel sidelined in a government that splits posts along sectarian and ethnic lines.
Disagreements have left Iraq without permanent ministers of defence and interior since the government was formed in 2010. Shi'ite leaders blame Sunni lawmakers for stalling, but Maliki's critics accuse him of amassing power.
"We believe the country is unbalanced," Nujaifi said. "All authority is exclusively under the control of a specific side and the participation of the other side is marginal."
Maliki, who spent years in underground exile from Saddam, accuses his Sunni partners of blocking the progress of government in an attempt to undermine his position.
The Shia premier and some allies have suggested he may call early elections before a scheduled 2014 vote as a way to break the deadlock that has delayed key legislation.
Maliki has proven adept at navigating the country's shifting political allegiances to keep his administration intact.
Many Sunnis want him to rein in the campaign against former Baath party members, but that could alienate some of Maliki's Shia backers before provincial elections in April.
Sunni parties are seeing signals from Maliki's National Alliance Shia coalition that there is room for negotiation. But those overtures are very preliminary, Nujaifi said.
"We've started receiving messages suggesting we turn the page of the past, discard disagreements and start from the beginning," he said. "If we cannot reach a deal, the country will slide back into many problems."