The group was established in 1948 as a breakaway split from the communist Tudeh Party of Iran, when they rejected the party's Stalinism and pro-soviet oil concession stance in favor of democratic socialism and centrist Marxism, supporting nationalization of the Iran oil industry movement.[1] They backed National Front and in 1951, joined socialist Toilers Party of the Iranian Nation, led by Mozzafar Baghai. Third Force split from the party in October 1952, after they positioned against Government of Mosaddegh.[6]