It was a major event in the modern history of Sri Lanka, as it was the first time the demand for a separate state for the Sri Lankan Tamils was made; Tamils had previously only demanded devolution or power sharing under a federal system.
[1][2][3] TULF contested the 1977 Sri Lankan parliamentary election on its demand for Tamil Eelam and won an overwhelming mandate in the Tamil areas, becoming the main opposition party in Sri Lanka, the only time a minority party has done so.
It gave impetus to Tamil nationalists, who claimed it was a democratic endorsement of a separate state.
Prior to this point, ethnic tensions between the Sinhala and Tamil residents of the island had been growing due to events like the passage of the Ceylon Citizenship Act, which stripped all Indian Tamils of the island of their citizenship, the passage of the Sinhala Only Act which made Sinhala the only official language of the country, as well as two pogroms in 1956 and 1958.
[9] The Tamil United Liberation Front demand for Tamil Eelam led the Sri Lankan Government to pass the 6th Amendment, which made it mandatory for all members of parliament to take an oath for the unitary state of Sri Lanka.