[3] He was educated in Magherafelt and spent a short time working in Social Security in the Civil Service of Northern Ireland before beginning training as a Free Presbyterian Church of Ulster minister.

[citation needed] McCrea was a Democratic Unionist Party (DUP) member of Magherafelt District Council from its creation in 1973 until he stood down to concentrate on Westminster duties in 2010, and topped the poll in every local government election he contested from 1973–2005.

He was Member of Parliament for Mid Ulster from 1983 but lost this seat to Sinn Féin chief negotiator and deputy First Minister Martin McGuinness at the 1997 election.

He took South Antrim at a by-election in 2000 caused by the death of Ulster Unionist Party MP, Clifford Forsythe, but failed to retain this seat at the 2001 election.

[8][9][10] In 1972, McCrea issued a press release, saying, "We call on all Loyalists to give their continued support to the Ulster Defence Association as it seeks to ensure the safety of all law-abiding citizens against the bombs and bullets of the IRA.

[10] McCrea also conducted the funeral service for Benjamin Redfern, a UDA member who died while trying to escape the Maze Prison in a bin lorry in August 1984.

[13] At the DUP annual conference of April 1986, McCrea interrupted councillor Ethel Smyth when she said she regretted the death of Sean Downes, a 24-year-old Catholic civilian who had been killed by a plastic bullet fired by the Royal Ulster Constabulary (RUC) during an anti-internment march in Andersontown in August 1984.

[16]In December 1986, McCrea aroused controversy when in an interview with Hot Press magazine following a recent threat by the "Ulster Freedom Fighters" (the UDA's cover name used to claim responsibility for attacks) to bomb Dublin, he commented that the Republic of Ireland "must reap what they sow" for its role in the Anglo-Irish Agreement.

[19] In February 1992 McCrea sent a message of sympathy to the family of RUC Constable Alan Moore, who had committed suicide after shooting dead three people and injuring two others at a Sinn Féin advice centre on the Falls Road, Belfast.

A Northern Ireland Office memo released under the thirty-year rule in December 2014 revealed that McCrea had called for the Royal Air Force to carry out "strikes against Dundalk, Drogheda, Crossmaglen and Carrickmore" at the DUP's annual conference in April 1986.