Until his resignation from the party in 2007, McKee was a Democratic Unionist Party (DUP) councillor. He is one of the longest serving councillors on Larne Borough Council; like the UUP's Roy Beggs, he has served continuously since the council was formed in 1973. Every council election he runs on the Larne Lough electoral district. He was also elected to the Northern Ireland Forum in 1996 and the Northern Ireland Assembly in 1982.
At an anti-Good Friday Agreement protest in Antrim on April 1998 McKee shared a platform with then fellow DUP member Sammy Wilson and Kenneth Peeples, a described leader of the Orange Volunteers and Protestant fundamentalist, who burned a copy of the agreement. In 2000 he was accused by fellow Larne councillor and Social Democratic and Labour Party member Danny O'Connor of raising tensions in the Catholic Seacourt estate by claiming Republicans were targeting the minority Protestant population in the estate. In 2004 Sinn Féin accused McKee of justifying an alleged death threat made to Danny O'Connor's mother who was verbally abused and threatened after loyalists erected a flag outside her house according to Sinn Féin. McKee has also spoken of his opinion that Larne Borough Council should not provide funding grants to Gaelic Athletic Association (GAA) teams as he stated the GAA is a sectarian organisation.
He served as Mayor of Larne in 1984/5, and as leader of the DUP group on Larne Borough Council for many years from 1981. His brother Bobby McKee is also a DUP councillor in Larne. Jack McKee resigned from the DUP in January 2007 in protest at the DUP's (later demonstrated) willingness to go into Government with the Irish republican political party, Sinn Féin. He subsequently joined Traditional Unionist Voice.
Heavy-handed policing by the Police Service of Northern Ireland (PSNI) on loyalist protesters was reason given by McKee for his resignation from the local District Policing Partnership. He was critical of the PSNI's handling of the disorder surrounding the removal of the Union Jack at Belfast City Hall near the sectarian interface at Short Strand, where he claimed republicans attacked loyalists protesters without police intervention.
- Sydney Elliott and W. D. Flackes, Northern Ireland: A Political Directory, 1968-1999, p.333
- Belfast Telegraph, Tuesday, February 13, 2007 – Niggling doubts over safe seats – Will DUP see dent in support through prospect of sharing power with SF?
- "'Demon Pastors' are humbled", The Guardian
- Sectarian attacks Iol.ie
- UDA threaten SDLP councillor's mother An Phoblacht
- This week back in 1995 Larne Times
- "TUV decision 'no slight'", Larne Times, 20 March 2008
- "McKee quits partnership body over ‘heavy-handed’ policing of protests" Larne Times 19 September 2013