It was established in 1952 as a breakaway from the ruling Eighth Army of Liberation, and was the country's first lasting nationwide political party.
In the 1957 elections it received almost half the national vote and won five of the eight seats.
In the 1966 elections it received fewer votes than the Saint Vincent Labour Party, but won one seat more.
Prior to the election several senior members of the party formed the Mitchell/Sylvester Faction.
The PPP's opposition to independence from the United Kingdom saw it reduced to just two seats, whilst the Labour Party won ten.