Nominations are to adjacent astatine aboriginal successful the contention to win Nicola Sturgeon arsenic SNP person and archetypal minister.
Three MSPs - Kate Forbes, Humza Yousaf and Ash Regan - person already said they volition stand.
No different candidates are expected to articulation the contention up of nominations closing astatine noon. Ms Regan volition formally motorboat her run soon up of the deadline.
The victor of the contention volition beryllium announced connected 27 March.
Candidates were required to get 100 nominations from astatine slightest 20 section enactment branches, with SNP members deciding the victor done a azygous transferrable ballot system.
The archetypal afloat week of the contention has focused connected the candidates' views connected societal issues, with Ms Forbes facing disapproval from wrong her ain enactment aft saying she would not person voted successful favour of cheery matrimony had she been successful Holyrood successful 2014.
Ms Forbes, a devout subordinate of the Free Church of Scotland, besides said she would not person voted for the Scottish government's sex reforms successful December and that, according to her spiritual beliefs, enactment extracurricular matrimony was "wrong".
Several of Ms Forbes backers person withdrawn their endorsements, with some Ms Sturgeon and Deputy First Minister John Swinney questioning whether idiosyncratic who holds her views would beryllium an due prime to pb the enactment and the country.
But a canvass published connected Friday suggested she was the astir fashionable campaigner among SNP voters.
The survey of 1,001 radical who voted for the enactment astatine the past Scottish Parliament election, carried retired by communications bureau The Big Partnership betwixt Monday and Wednesday, recovered 28% favoured Ms Forbes arsenic the adjacent leader, against 20% for Mr Yousaf and 7% for Ms Regan. About 30% were undecided.
The canvass besides recovered that the outgo of surviving situation was regarded arsenic the astir important issue, followed by the economy, the NHS and education. Only 5% said they thought that the caller leader's religion oregon idiosyncratic beliefs were important.
Paul Robertson, caput of nationalist affairs astatine The Big Partnership said the canvass suggests that the absorption of the enactment predetermination truthful acold does not bespeak the priorities of SNP supporters.
On Thursday Ms Forbes attempted to reset her campaign, saying she felt "greatly burdened" that immoderate of her comments had caused hurt, and pledging to "defend to the hilt" the rights of each radical successful Scotland to unrecorded without fearfulness oregon harassment.
Mr Yousaf, the country's wellness secretary, has picked up the astir endorsements from SNP politicians, with elder MSPs specified arsenic Shirley-Anne Somerville, Jenny Gilruth, Maree Todd and Neil Gray among his supporters.
He has faced disapproval implicit the authorities of the NHS, with waiting times successful Scotland's hospitals. Opposition parties person claimed helium was the "worst wellness caput since devolution" and that helium should beryllium sacked alternatively than promoted.
Ms Sturgeon defended Mr Yousaf's grounds astatine archetypal minister's questions connected Thursday, saying that the issues faced by the wellness work successful Scotland were shared by different parts of the UK and pointing retired that Scotland has avoided onslaught enactment by NHS staff.
Mr Yousaf, who is Muslim, missed the 2014 adjacent marriages ballot astatine Holyrood arsenic helium was astatine a meeting, but supported the transition of the measure during its earlier stages successful the parliament.
One erstwhile SNP minister, Alex Neil, told the Herald newspaper connected Friday that Mr Yousaf had contrived to "skip" the ballot by arranging this gathering 19 days successful advance, and that it could person been rescheduled.
Mr Yousaf has vigorously denied specified suggestions, and said the occurrence was being utilized by opponents to undermine his campaign.
He said the intent of the gathering was to sermon the lawsuit of a Scottish national connected decease enactment with the Pakistan consulate.
Ms Regan, who discontinue arsenic assemblage information curate implicit the government's sex designation reforms, has said she supports cheery matrimony and has called for an extremity to "mudslinging" successful the enactment contest.