Yogeswaran was the son of Shanmugam Appakkutti Vettivelu, a medical doctor from Jaffna in northern Ceylon, and Parasakthi.

[1][2] Yogeswaran was an active member of the Illankai Tamil Arasu Kachchi (Federal Party) and its youth wing.

[5][6][7][8] A keen supporter of TULF, Yogeswaran was a member of its Action Committee and in charge of youth affairs.

[10][11] Yogeswaran and all other TULF MPs boycotted Parliament from the middle of 1983 for a number of reasons: they were under pressure from Sri Lankan Tamil militants not to stay in Parliament beyond their normal six-year term; the Sixth Amendment to the Constitution of Sri Lanka required them to swear an oath unconditionally renouncing support for a separate state; and the Black July riots in which up to 3,000 Tamils were killed by Sinhalese mobs.

[4][13] Yogeswaran later returned to Jaffna after getting permission from the rebel Liberation Tigers of Tamil Eelam (LTTE) but was kept under virtual house arrest by them until the arrival of the Indian Peace Keeping Force in July 1987.

[13] Yogeswaran and his wife moved into a house in Bullers Road (Baudhaloka Mawatha) in the Cinnamon Gardens area of Colombo.

[4][13] In effort to bring about unity amongst the Tamils, Yogeswaran made contact with the LTTE and met with them several times.