The race to succeed Wendy Alexander as leader of Scottish Labour is set to begin with the three main contenders all but established.
Results will not be known until mid to late September but the party's procedure committee is now arranging to meet with nominations to be invited immediately afterwards.
Three former Cabinet ministers are considered frontrunners: Iain Gray, Cathy Jamieson and Andy Kerr.
Further candidates could include fellow MSPs Ken Macintosh and Charlie Gordon, but it is uncertain if they will be able to secure sufficient nominations. Margaret Curran was also expected to enter the contest, but her defeat in Glasgow East appears to have dampened the chances of that happening.
Indeed, the leadership contest itself has been delayed by the by-election.
Mr Kerr has said he wants to post of the Scottish leader to have more power.
Speaking to BBC Radio Sctoland, Mr Kerr said: "I have to say I think the leader in Scotland needs to have a much wider voice, a much more influential voice and a much stronger voice.
"That's what I intend to say during the campaign."
It was triggered by the resignation of Ms Alexander after the Scottish parliament's standards committee banned her from parliament for one day following a failure to declare donations on her register of interests.
Party MSPs, MPs members and affiliated unions will be eligible to vote.
The unofficial opening of the contest follows news of the death of former Scottish Liberal Democrat leader Lord Russell-Johnston. He was also MP for Inverness, deputy leader and a member of the Council of Europe's Parliamentary Assembly.
Lib Dem leader Nick Clegg called him "an institution in his own right".