Sri Lanka's ruling party on Wednesday named plantations minister D M Jayaratne, a close ally of President Mahinda Rajapakse, as prime minister of the new parliament.
Jayaratne, 67, was due to be sworn in later in the day by the president, who is both head of state and government.
Jayaratne is a party stalwart who became a member of parliament in 1970 after a career as a postman in the central district of Kandy.
As a senior member of the left-leaning Sri Lanka Freedom Party, the main constituent in the ruling United People's Freedom Alliance (UPFA), Jayaratne was a leading candidate for the number-two role.
The UPFA won 144 seats in the 225-member assembly at the April 8 elections, giving it a majority just short of a two-thirds needed to rewrite the constitution, which currently prevents Rajapakse running re-election in 2016.
The job of prime minister is largely ceremonial in Sri Lanka but, in the event of the president's death, the holder would be expected to step into the top role.