A Sunni Muslim lawyer who had been invited to join a committee that will draft the Iraqi constitution has been shot dead with his 15-year-old son.
Relatives expressed their shock at the killings
Jasim al-Issawi, 50, and his son, died when gunmen opened fire on their car in Baghdad's north-western Shula district, the interior ministry said.
Mr Issawi had declined the invitation to be one of 15 Sunnis on the parliamentary constitutional panel.
Insurgents have threatened Sunnis who join the political process.
Saleh al-Mutlak, secretary general of the Sunni National Dialogue Council, said Mr Issawi was asked last week to join the panel but refused.
"He just wanted to make way for other people whom he thought were more qualified than him. He was a moderate person," he told news agency AFP.
"We have received numerous warnings that there is a campaign to liquidate Sunnis before the next round of elections. I blame Iran and its followers."
Mr Issawi was a law professor at Baghdad University and the former editor-in-chief of Al-Siyadah newspaper.
Last week, Shia leaders agreed to allow Sunnis to take 15 of the constitutional committee's 55 seats as well as having 10 advisory seats.
It is hoped the involvement of Sunnis in Iraq's political process will undermine support for the insurgency among some members of the Sunni community.