Nominations for the post of SNP Westminster group leader are set to open to MPs.
The party is selecting another MP for the role after Angus Robertson lost his seat in last week's General Election.
The new group leader will be announced on Wednesday evening.
Mr Robertson lost his Moray seat, which he had held since 2001, to the Conservatives.
He was beaten by former MSP Douglas Ross by 18,478 votes to 22,637.
Mr Robertson became one of the SNP's most high-profile figures after the 2015 election, thanks to a weekly platform at Prime Minister's Questions.
The SNP won 35 seats in last week's election, down 21 from 2015.
First Minister Nicola Sturgeon has admitted the issue of another independence ballot was a factor in last Thursday's vote, and said the party will reflect on its plans amid calls for it to be taken off the table.
She has turned her focus to the UK's Brexit approach as political leaders including Scottish Conservative leader Ruth Davidson call for more consensus.