The United Front was a political alliance in Sri Lanka, formed by the Sri Lanka Freedom Party (SLFP), the Lanka Sama Samaja Party (LSSP) and the Communist Party of Sri Lanka (CPSL) in 1968. It came to power in the 1970 general election, but broke up in September 1975.
It was conceived by the LSSP as a front of the working class - represented by itself and the CPSL - with the petty bourgeoisie - represented by the SLFP - and by the CPSL as a front of progressive forces.
References
United Front (Sri Lanka) Wikipedia(Text) CC BY-SA