Nominations have formally opened in the race to replace Carwyn Jones as Welsh Labour leader and first minister.
Mr Jones triggered the leadership contest in a letter to party chair Margaret Thomas on Wednesday.
Candidates need the support of five other AMs to get on the ballot paper and nominations close next week.
Most AMs are backing Finance Secretary Mark Drakeford, while five are supporting his cabinet colleague, Health Secretary Vaughan Gething.
The ballot will be held in November and result will be announced in early December.
Mr Jones intends to resign following his final First Minister's Questions on 11 December.
He announced his intention to quit at the Welsh Labour conference in April.
On Monday, Mr Jones said he would be willing to nominate Eluned Morgan, Minister for Welsh Language and Lifelong Learning, following a row over the lack of a woman candidate on the ballot.
With four other AMs backing her, Mr Jones' move virtually guaranteed her place in the contest.
Voting papers will be sent to Labour Party members in Wales, as well members of affiliated trade unions and organisations.
The ballot closes on Monday 3 December.
Earlier this month, Welsh Labour decided to use the one-member-one-vote system, like the one that elected Jeremy Corbyn, for the poll.
Previously it used an electoral college process for such contests, which split the votes three ways between members, unions and politicians.
It sometimes resulted in victories by candidates whose rival had more support from party members, most recently when Carolyn Harris beat Julie Morgan to become deputy leader of Welsh Labour in April.