The party was founded on 31 July 1986. It emerged from an earlier group, the People's Movement for Independence against Neo-Colonialism and Capitalism in The Gambia (PMINCC), whose members included Halifa Sallah, Sam Sarr, Amie Sillah, Adama Bah and Momodou Sarho. The PMINCC were also believed to be the publishers of the newspaper The Voice of the Future, and six members were put on trial for its publication in 1984, although all were acquitted.
Initially, the PDOIS had no official leader until December 1997, when Sidia Jatta was chosen as its first leader. It began publishing its own newspaper, Foroyaa, in July 1987, where it was critical of the pro-Western foreign policy of Dawda Jawara, and opposed the Senegambia Confederation. In 1987, it put forward five candidates in the parliamentary election, but all were defeated. In 1992, it put forward 14 candidates, but again, all were defeated. Jatta stood in the presidential election that year, and came fourth, winning 5.24% of the vote. The PDOIS was not banned following the 1994 coup by Yahya Jammeh as it did not publicly denounce it, but both Jatta and Sallah turned down the cabinet posts they were offered.
Jatta won 3% of the vote in the 1996 and 2001 presidential elections. In the 1997 parliamentary election, Jatta won their first seat in the National Assembly of Wuli West. In 2002, Jatta retained the seat and Sallah additionally won the seat of Serekunda Central. From 2002 to 2007, PDOIS was the largest opposition party in the National Assembly, and Sallah served as Leader of the Opposition. In 2005, the PDOIS joined the National Alliance for Democracy and Development (NADD), and Sallah was selected as the NADD candidate in the 2006 presidential election, but only won 6% of the vote. In the 2007 parliamentary election, NADD only won one seat, Jatta's, with Sallah losing his.[1]
