The Federal Party (Sri Lanka) (FP) became the most dominant Tamil political party in 1956 and lobbied for a unitary state which gave Tamil and Sinhalese equal rights, including recognition of two official languages (Tamil and Sinhala) and considerable autonomy for the Tamil areas. It was against this backdrop that the Federal party decided to sign the Bandaranaike-Chelvanayakam Pact in July 1957. However, soon afterwards the agreement was abandoned by the Sinhala party. In 1965, another pact, the Senanayake-Chelvanayakam pact was signed but also not implemented. The failure of the Sinhalese dominated government to implement devolutionary agreements through the 1950s and 1960s, abrogation of power-sharing promises, worsening economic conditions, and lack of territorial autonomy caused further disillusionment and isolation
among northern Tamils. 

In the 1970 election the United Front (UF) led by Sirimavo Bandaranaike came into power. The new government adopted two new policies that were considered discriminatory by the Tamil people. First, the government introduced a discriminatory system regulating university admissions, specifically targeted at reducing the intake of overachieving Tamils and other minorities in the Sri Lankan educational system. The scheme allotted up to 40% of the university placement to rural youth (primarily from Sinhala areas). The government claimed that this was an affirmative action scheme to assist geographically disadvantaged students to gain tertiary education. According to K.M. de Silva, a historian, the system of standardisation of marks required the Tamil students to achieve higher marks than the Sinhalese students to get into university. A similar policy was adapted for employment in the public sector, leaving less than 10 percent of civil service jobs available to Tamil speakers. The Federal Party opposed these policies and Chelvanayakam resigned his parliamentary seat on October 1972. The new constitution in 1972 further exacerbated long standing grievances and sense of discrimination for the Sri Lankan Tamil people. This had emboldened younger Tamils to seek ways to form a Tamil homeland (nation) where the rights and freedoms of the Tamil people could be protected and nurtured. 

In 1973, Tamil parties' call for regional autonomy was replaced with the demand for a separate state called Tamil Eelam. Two years later, in 1975, all Tamil political parties merged together and became known as the Tamil United Liberation Front (TULF). On 1976, the first national convention of the Tamil United Liberation Front was held at Vaddukodai, where the party adopted a unanimous resolution called the Vaddukodai Resolution. This resolution charged that the Sinhalese government, with the use of the constitution of 1972, had used its power to "deprive the Tamil nation of its territory, language, citizenship, economic life, opportunities of employment and education thereby destroying all the attributes of nationhood of the Tamil people." The resolution further called for the "Free, Sovereign, Secular Socialist State of TAMIL EELAM".

As a result of the Vaddukodai resolution, the Tamil United Liberation Front became the first Tamil political party to run its campaign on a separatist platform. It swept the parliamentary elections in the Tamil-dominated districts of the North and East in 1977, winning 18 seats and became the largest opposition in Parliament. The reason for the success of the TULF was seen as the result of growing Tamil agitation for self-determination. 

During the time of the Vaddukodai declaration, there were several Tamil militant organizations who believed that armed struggle was the only way to protect the sovereignty of the Tamil areas. TULF, however, believed in peaceful parliamentary ways towards achieving a solution. Though the TULF had adapted a separatist platform, they were still open to peaceful negotiations and decided to work towards a political agreement with President J.R Jayewardene. The outcome was the District Development Councils scheme (DDC) passed in 1980. The District Development Councils scheme was based, to some extent, on decentralization of the government within a united Sri Lanka. DDCs were soon abandoned because the two sides were not able to agree to the number of District Ministers in the Tamil districts. In 1983 the Sixth Amendment was passed and required Tamil members of parliament and Tamils in public office to take the oath of allegiance to the unitary state of Sri Lanka. The Sixth Amendment forbade advocating a separate state even by peaceful means. Consequently, the TULF was expelled from the parliament for refusing to take the oath.

Democratic Norwegian Council of Eelam Tamils
Pongu Tamil
Tamil referenda on the formation of Tamil Eelam
Concept