McGrane was conhvicted of
Provisional IRA membership in 1976 and imprisoned for a year. As chairman of the Provisional IRA Army Executive, McGrane played a leading role in mounting serious opposition to attempts by
Sinn Féin leader
Gerry Adams to depart from the original principles of the organisation. He was amongst a number of IRA members who left over acceptance of the
Mitchell Principles, which required decommissioning of its arsenal. In November 1997, McGrane joined former IRA quartermaster-general,
Michael McKevitt, in forming the hardline Real IRA which opposed the IRA ceasefire. It was one of a number of small dissident republican groups that rejected the
Good Friday Agreement and the peace process and were committed to continuing with an armed struggle against what they considered forces of occupation. At the formation of the Real IRA, McGrane was appointed director of training. In 1999 he was arrested training recruits in the use of firearms, during a Real IRA training session for which he was also jailed for four years by the Special Criminal Court. The arrest followed an operation carried out by the
Garda Emergency Response Unit. ==Óglaigh na hÉireann==