All Labor members in Tasmania will vote for a new state leader, making the state the first to allow rank and file members a say in who leads them.
Labor's rank and file members will vote in a ballot to elect the party's next Tasmanian leader.
The ALP state branch has voted to allow members, union delegates and MPs each a one-third say in who the leader should be following the election loss 10 days ago.
Tasmanian Labor becomes the first in any state or territory to give rank and file members a vote.
It follows the party's move to a similar model nationally after last year's federal election loss.
Kevin Rudd introduced the membership ballot on his return to the prime ministership and after Labor's election loss Bill Shorten beat Anthony Albanese under the new rules to become leader.
Tasmanian state secretary John Dowling said the party's administrative committee had unanimously backed the move.
He said the ballot would be open to any person who joined the ALP before April 10.
"This is a fantastic opportunity for Labor supporters to join the ALP and have their say in who they think the Labor leader should be," Mr Dowling said in a statement.
Outgoing premier Lara Giddings has indicated she wants to continue as opposition leader.
Her deputy Bryan Green is reportedly being urged to run by party heavyweights.
A one-third weighting will be given to rank and file members, state MPs and the 100 union delegates elected to last year's state conference.
Nominations will close on April 3 and the deadline for ballot papers is April 23.
The leader will be announced the next day.
The final make-up of the parliamentary Labor party remains unknown with seats still in doubt as preference counting continues.
The final count is expected to be completed by the end of the week.