Octogenarian Tamil lawmaker Rajavarothiam Sampanthan of the Tamil National Alliance was selected to lead the opposition by the speaker of Parliament, Karu Jayasuriya on Thursday.
Sampanthan expressed his gratitude to the House for selecting him as the Opposition Leader.
"I also wish to thank all the people of the North and East who kept their faith in us at the General Elections, and the party for appointing me as the party's Parliamentary Group Leader".
"We will support the government for its all good deeds that are done for the betterment of people and oppose it only when necessary".
Sampanthan is the second ethnic Tamil after Appapillai Amirthalingam to lead the opposition in Sri Lanka in three decades.
Appapillai Amirthalingam became opposition leader in 1977 but resigned five years later after refusing to swear that he would not promote a separate state for Tamils.