Question: What group initially known as Official Sinn Féin, featured activist Des O'Hagan?

Context paragraphs:
Sinn Féin Bank: The Sinn Féin Bank, formally the Sinn Féin Co-operative People's Bank, Ltd. (Irish: "Coṁar-Ḃannc Sinn Féin, Teo." )  was a co-operative bank in Ireland associated with the Sinn Féin movement, which operated from August 1908 to October 1921.  The Sinn Féin Bank is sometimes confused with the National Land Bank, established as a friendly society in 1919 with Dáil backing and premises at 5 Harcourt Street.

Sinn Féin Funds case: The Sinn Féin Funds case ("Buckley and Others v. the Attorney-General and Another") was a 1942–48 Irish court case in which the Sinn Féin party claimed ownership of funds deposited with the High Court in 1924 which had belonged to the Sinn Féin party before 1923.  The Sinn Féin Funds Act 1947, which attempted to halt the court case and assign the funds to Bord Cistí Sinn Féin, was ruled unconstitutional by the Supreme Court in an important judgement on separation of powers and private property rights.  The original action was subsequently decided against Sinn Féin, on the basis that the pre-1923 party was separate from the 1940s party.  Most of the disputed funds were consumed by legal costs.

John Joe Rice: John Joe Rice (died 1 July 1970) was an Irish Sinn Féin politician.  He was elected as a Sinn Féin Teachta Dála (TD) for the Kerry South constituency at the 1957 general election.  He did not take his seat in the Dáil as Sinn Féin ran on an abstentionist ticket.  He was one of four Sinn Féin TDs elected at the 1957 general election, the others were Ruairí Ó Brádaigh, John Joe McGirl and Eighneachán Ó hAnnluain.  He was defeated at the 1961 general election.

Republican Sinn Féin: Republican Sinn Féin or RSF (Irish: "Sinn Féin Poblachtach" ) is an Irish republican political party in Ireland.  RSF claims to be heirs of the Sinn Féin party founded in 1905 and took its present form in 1986 following a split in Sinn Féin.  RSF members take seats when elected to local Irish councils but do not recognise the validity of the partition of Ireland and subsequently the legitimacy of the Northern Ireland (Stormont) or Republic of Ireland (Leinster House) parliaments, so the party does not register itself with them.

Republican News: Republican News was a longstanding newspaper/magazine published by Sinn Féin.  Following the split in physical force Irish republicanism in the late 1960s between the "Officials" (Official Sinn Féin — also known as Sinn Féin Gardiner Place — and the Official IRA) and the "Provisionals" (Provisional Sinn Féin — also known as Sinn Féin Kevin Street and now most commonly simply as Sinn Féin — and the Provisional IRA) "Republican News" was eclipsed by "An Phoblacht", a new magazine launched by Provisional Sinn Féin in 1970.  "An Phoblacht" came first and then in early 1970, Joe Graham and Proinsias Mac Airt put together "The Republican News" and it functioned independently for quite a while.  Graham worked on only three issues of it before starting "The Vindicator".  The magazines merged under the name "An Phoblacht/Republican News" in 1979.

Sinn Féin (slogan): Sinn Féin ("ourselves" or "we ourselves") and Sinn Féin Amháin ("ourselves only / ourselves alone / solely us") are Irish-language phrases used as a political slogan by Irish nationalists in the late nineteenth and early twentieth century.  While advocating Irish national self-reliance, its precise political meaning was undefined, variously interpreted as the aim of a separate Irish republic or (as advocated by Arthur Griffith) that of a dual monarchy.  Its earliest use was to describe individual political radicals unconnected with any party and espousing a more "advanced nationalism" than the Irish Home Rule movement.  In the 1890s "Sinn Féin, Sinn Féin amháin" was the slogan of the Gaelic League, which advocated the revival of the Irish language.

Des O'Hagan: Des O'Hagan (29 March 1934 - 5 May 2015) was a prominent member of the Workers' Party of Ireland and was a founding member of the Northern Ireland Civil Rights Association.

Workers' Party of Ireland: The Workers' Party (Irish: "Páirtí na nOibrithe" ), originally known as Official Sinn Féin, is a Marxist–Leninist political party active throughout Ireland.  The party originated with a split between factions of Sinn Féin (which was founded in 1905) and the Irish Republican Army (IRA), which took place in 1969–70, early in the Troubles.  The faction that broke away became known as the Provisional Irish Republican Army and Provisional Sinn Féin.  The Officials' leaders at the time the Provisionals left were Cathal Goulding and Tomás Mac Giolla.

United Irishman (1948 newspaper): The United Irishman/An tÉireannach Aontaithe, first published in May 1948, under Michael Traynor, was the official monthly organ of Sinn Féin sold by its members.  After the split in the Irish Republican Movement, the title continued as the organ of Official Sinn Féin, being published from the offices in 30 Gardner Place in Dublin, with the Provisional wing publishing An Phoblacht.  The first editor was Seán G. O'Kelly based in an office in 38 South King Street in Dublin.  The historian Éamonn MacThomáis edited the paper for a short while prior to the 1970 split in Sinn Féin.  Other editors of the paper included Seán Cronin, Seán Ó Brádaigh (1958–1960), Ruairí Ó Brádaigh, Eoin Ó Murchú, Jackie Ward, Seamus Ó Tuathail, Denis Foley and Tony Meade (1967).  Contributors to the paper included Eamon McCann, Roy Johnston, Eamon Smullen, Eoghan Harris and Sean Garland.  The "United Irishman" was replaced with "The Irish People" and the "Workers' Weekly" in 1980.

Sinn Féin (newspaper): Sinn Féin was a weekly Irish nationalist newspaper edited by the Dublin typesetter, journalist and political thinker Arthur Griffith.  It was published by the Sinn Féin Printing & Publishing Company Ltd. (SFPP) between 1906 and 1914, and replaced an earlier newspaper called the "United Irishman" which was liquidated after a libel suit.  The SFPP brought out the "Sinn Féin Daily" in 1909 but had to abandon it when it plunged the company into enormous debt.  The "Sinn Féin" weekly and the SFPP both came to an end when they were suppressed by the British Government in 1914.

Supporting paragraphs: Des O'Hagan Workers' Party of Ireland
Answer: Workers' Party of Ireland