Irish Republican Socialist Party

The Irish Republican Socialist Party or IRSP (Irish: Páirtí Poblachtach Sóisialach na hÉireann) is a minor communist, Marxist–Leninist and Irish republican party in Ireland. It is often referred to as the "political wing" of the Irish National Liberation Army (INLA) paramilitary group. The party's youth wing is the Republican Socialist Youth Movement (RSYM). It was founded by former members of 'Official' Sinn Féin in 1974 during the Troubles. The party opposes the Good Friday Agreement and the European Union.

The Irish Republican Socialist Party was founded at a meeting on 8 December 1974 in the Spa Hotel in Lucan, near Dublin, by former members of Workers' Party (aka 'Official' Sinn Féin), headed by Seamus Costello. He had been expelled from the Official Irish Republican Army (OIRA) following a court-martial, and from Official Sinn Féin on the same basis. Along with other activists, he was dissatisfied with the group's tactics and policies, especially on the issues surrounding the 1972 OIRA ceasefire and his growing belief that the emerging conflict was sectarian. According to the IRSP, 80 people were in attendance. A paramilitary wing, the Irish National Liberation Army (INLA), was founded the same day, although its existence was intended to be kept hidden until such a time that the INLA could operate effectively. Costello was elected as the party's first chairperson and the Army's first chief of staff. Together, the IRSP and the INLA were referred to as the Irish Republican Socialist Movement (IRSM).

Former Unity MP for Mid-Ulster Bernadette McAliskey served on the executive of the IRSP. In December 1975 she resigned following the failure of a motion to be passed which would have brought the INLA under the control of the IRSP Ard Comhairle (executive committee). This led to the resignation of half the Ard Comhairle, which weakened the party. Tony Gregory, a future Dublin TD, was also a member for a short time.

In one of the first of the INLA's armed operations, Billy McMillen, commanding officer of the OIRA Belfast Battalion, was murdered by INLA member Gerard Steenson.

On 5 October 1977, Costello was shot dead in his car by a man armed with a shotgun. His supporters blamed the Official IRA for the killing.

The party's poor showing in the 1977 Irish general election, resignations, and the assassination of Costello, weakened the organisation.

In 1980, several IRSP and INLA members—including John Turnley, Miriam Daly, Ronnie Bunting and Noel Little—were killed by Ulster loyalist paramilitaries, most prominently the Ulster Defence Association (UDA). The IRSP have contended that the killings were a result of collusion between loyalists and security forces, even suspecting that some of the killings were carried out by the SAS with responsibility attributed to the UDA.

Three members of the INLA and IRSP died in the 1981 Irish hunger strike in HM Prison Maze, also known as Long Kesh: Patsy O'Hara, Kevin Lynch, and Michael Devine.