The SDLP party platform advocates Irish reunification[3] and, pending the unity of all the people of Ireland and while the northern jurisdiction remains part of the United Kingdom, further devolution of powers.

Established during the Troubles, a significant difference between the two parties was the SDLP's rejection of violence, in contrast to Sinn Féin's then-support for (and organisational ties to) the Provisional IRA and physical force republicanism.

[16] The SDLP initially rejected the Nationalist Party's policy of abstentionism and sought to fight for civil rights within the Stormont system.

[17] However, the SDLP quickly came to the view that Stormont was unreformable, refusing to attend the state opening on 18 June 1971, and withdrawing altogether in response the shooting dead of Seamus Cusack and Desmond Beattie in Derry on 8 July.

It also proposed the establishment of a National Senate drawn equally from a devolved Assembly in Belfast and the Oireachtas in Dublin to plan for the integration of the island.

[22] Paddy Wilson, the SDLP’s General Secretary and councillor in the new Belfast City Council was murdered on the 26 June, two days before the election to the new Northern Ireland Assembly.

[24] Negotiations occurred throughout October and November on the formation of a new power-sharing Executive to govern Northern Ireland with the SDLP, UUP and Alliance taking part.

On 21 November Northern Ireland Secretary of State, William Whitelaw, announced that agreement had been reached on the composition and functions of the new Executive, with the SDLP entitled to four of the eleven members and a further two non-Executive office holders.

[25] Following discussions between the British Prime Minister and Irish Taoiseach, as well as the political parties, it was announced on 9 December at Sunningdale that an agreement had been reached on the remaining elements of the White Paper, including the implementation of a Council of Ireland.

The anti-power-sharing Unionists united under the UUUC banner and won 11 seats, with Gerry Fitt being the only pro-power-sharing MP returned, dealing a critical blow to the fledgling Executive.

[28] The UUUC however won a majority of seats and votes, the Constitutional Convention made no progress and the British Government brought it to an end in early 1976.

As the strikes went on, SDLP leader John Hume met Prime Minister Margaret Thatcher to ask that she concede some of the demands of the hunger strikers.

[38] In Spring 1982 Northern Ireland Secretary of State Jim Prior proposed “rolling devolution” by which a consultative Assembly be established.

As a result of Seamus Mallon’s membership of Seanad Éireann he was removed as a member of the Assembly and a by-election was held in Armagh the following spring.

It was a forum “all democratic parties which reject violence and which have members elected or appointed to either House of the Oireachtas or the Northern Ireland Assembly”.

The Forum met for the first time on 30 May with five SDLP members: John Hume, Austin Currie, Joe Hendron, Eddie McGrady and Seamus Mallon.

[41] In the general election in June 1983 the SDLP failed to regain the seat in Belfast West it had lost when Gerry Fitt resigned from the party.

[44] The “Four Horsemen” and other senior politicians persuaded President Ronald Reagan to encourage British Prime Minister Margaret Thatcher to work with the Irish Government to agree a collective way forward.

The SDLP targeted constituencies where support for the Anglo-Irish Agreement was strongest and subsequently managed to win Newry and Armagh, where deputy leader Seamus Mallon won the seat from the Ulster Unionists.

[46] This success continued into the 1987 general election where the SDLP’s support for the agreement saw its vote rise to levels last seen when the party was first founded in the early 70s, mostly at the expense of Sinn Féin.

[47] In January 1988 SDLP Leader John Hume began a series of secret talks with Sinn Féin President Gerry Adams which lasted until August of that year.

[50] In April 1992 the SDLP reached their electoral high point, as Joe Hendron won the Belfast West seat at the expense of Gerry Adams.

The talks would eventually lead to the Downing Street Declaration by British Prime Minister John Major and Taoiseach Albert Reynolds, which laid the ground for a ceasefire and negotiations.

[52] Throughout 1994, SDLP representatives continued to face attacks from paramilitaries, as loyalists burnt out Joe Hendron’s car while Councillor John Fee was beaten by Republicans outside his home.

SDLP Leader John Hume stated that this would only be considered in the event of an IRA ceasefire and Sinn Féin agreeing to end their policy of abstentionism.

"[67] After his election as Fianna Fáil Leader in January 2011, Micheál Martin repeatedly dismissed the possibility of a merger or electoral alliance with the SDLP.

[71] In the lead up to the 2022 Assembly election, party leader Colum Eastwood played down the partnership stating, "The SDLP stands on its own two feet.

At the swearing in ceremony after the 2019 general election, the party leader Colum Eastwood said: The SDLP, along with Sinn Féin, have long sought speaking rights in Dáil Éireann, the lower house of the Republic's parliament.

In 2005, Taoiseach Bertie Ahern, leader of Fianna Fáil, put forward a proposal to allow MPs and MEPs from Northern Ireland to participate in debates on the region.

[107] Some see the SDLP as first and foremost a party now representing Catholic middle-class interests, with voters concentrated in rural areas and the professional classes, rather than a vehicle for Irish nationalism.