Jevgeni Ossinovski has been appointed chair of the Social Democratic Party (SDE) parliamentary group at the XIV Riigikogu, which convened on Thursday.
Mr Ossinovski is also party leader and a former health minister. Riina Sikkut, his successor at the ministry of health and labour has been appointed deputy chair.
SDE, which won 10 seats at the 3 March election, has not been involved in any coalition talks.
Ms Sikkut had not been elected to the XIII Riigikogu and was appointed health minister last May, from the office of the State Chancellory, so becomes a sitting MP for the first time (government ministers in Estonia do not sit in the Riigikogu).
Other SDE Mps include outgoing culture minister Indrek Saar, outgoing interior minister Katri Raik, and former foreign minister Marina Kaljurand. Outgoing foreign minister, Sven Mikser, ran for the post of speaker of the house, but was defeated by Henn Põlluaas (EKRE) who received 55 votes for the role in the 101-seat Riigikogu on Thursday.
Kaja Kallas, Martin Helme and Kadri Simson have been selected as parliamentary group leaders for the Reform Party, the Conservative People's Party of Estonia (EKRE) and the Centre Party respectively. Isamaa has yet to appoint a permanent parliamentary group leader. Isamaa party leader Helir-Valdor Seederis running as deputy speaker, so the party is due to appoint its parliamentary group chair next week, Isamaa told ERR on Thursday.
Editor: Andrew Whyte