McNamee was educated at St Patrick's College, Armagh, Abbey Grammar School, Newry and at the University of Ulster.
As a member of Sinn Féin, his first electoral success was as a representative on the Northern Ireland Forum, representing Newry and Armagh from the forum's creation in 1996, until it was dissolved in 1998.
He did not stand for re-election to the Assembly in 2003, and resigned from Sinn Fein ahead of the 2005 local elections, during which he stood down as a councillor.
When Paul Quinn (21) of Cullyhanna was brutally beaten to death by a gang of men wearing balaclavas and overalls in October 2007, McNamee joined the Quinn Support Group to seek justice for his family.
He contributed to a Spotlight programme on BBC in November 2007 and stated that he believed that 'members of the provisional IRA were responsible for Paul Quinn's death