The agreement was the result of a year's negotiations between the two parties, and broadly outlined common goals in the areas of the economy, ethnic harmony, democracy, culture and foreign policy, areas in which the two parties shared common disagreements with the ruling UNP-led United National Front, which was in power at the time.

[2] The coalition was, in effect, an attempt to oust the ruling UNP based on negative public opinion of its handling of the Sri Lankan Civil War, both in terms of its approach to negotiating with the LTTE and a perceived free hand given to Western interference in the country's democracy through the Norwegian-led peace process.

The 2005 election has since been plagued by accusations of manipulation, with opponents of Rajapaksa and the UPFA accusing Rajapakse of paying off the LTTE to force ethnic Tamils to boycott the election through its proxy the Tamil National Alliance, depriving Wickremesinghe of a key part of the UNP's electoral base.

Mahinda Rajapaksa contested the presidential election again in January 2010 as the UPFA candidate, defeating the New Democratic Front's Sarath Fonseka, Rajapska's erstwhile ally and former Commander of the Sri Lanka Army.

[33][34][35] Deepening rifts within the Sri Lanka Freedom Party emerged during Rajapaksa's presidency, culminating in SLFP General Secretary and Minister of Health Maithripala Sirisena defecting from the UPFA on 21 November 2014 to contest the 2015 presidential elections as part a candidate of the UNP-led New Democratic Front.

[40] Sirisena won the prematurely-called election with a 51.28% majority, and appointed UNP leader Ranil Wickremesinghe as the prime minister of a transitional coalition government dominated by the UNP and supported by Sirisena loyalists in the SLFP and UPFA, while the faction of Rajapaksa loyalists decided to sit in the opposition.

[44][45][46] On 9 February, the Rajapaksa faction (consisting of 52 of the 95 UPFA MPs elected) formed an informal coalition named the Joint Opposition and sat in the opposition acting as an independent faction of the UPFA, citing, among other factors, Sirisena's defection and cooperation with the UNP as a betrayal to core SLFP/UPFA voters and principles.

[47][48] The MoU was allowed to lapse in April 2017 and was not renewed; senior UPFA members have cited the results of the bond issuance scam investigation as being a key point of contention between the two political entities and a central determinant of future collaboration with the UNP.