Founded in 1955, the St. Vincent Labor Party (SYLP), under R. Milton Cato, gained the support of the middle class. With a conservative law-and-order message and a pro-Western foreign policy, the SYLP dominated politics from the mid-1960s until the mid-1980s. Following victories in the 1967 and 1974 elections, the SYLP led the island to independence, winning the first post-independence election in 1979. Expecting an easy victory for the SYLP in 1984, Cato called early elections. The results were surprising: with a record 89% voter turnout, James F. Mitchell's New Democratic Party (NDP) won nine seats in the house of assembly.

Since the 1984 election, politics in St. Vincent have been dominated by the NDP. Bolstered by a resurgent economy in the mid-1980s, Mitchell led his party to an unprecedented sweep of all 15 house of assembly seats in the 1989 elections. The opposition emerged from the election weakened and fragmented but was able to win three seats during the February 1994 elections under a "unity" coalition. In 1998, Prime Minister Mitchell and the NDP were returned to power for an unprecedented fourth term but only with a slim margin of 8 seats to 7 seats for the Unity Labour Party (ULP). The NDP was able to accomplish a return to power while receiving a lesser share of the popular vote, approximately 45% to the ULP's 55%. In March 2001, the ULP, led by Ralph Gonsalves, assumed power after winning 12 of the 15 seats in Parliament.

In the December 2005 parliamentary elections, Prime Minister Gonsalves and the ULP retained their 12-3 majority over the NDP.