Transport Minister Keith Brown is expected to announce today that he is standing for the deputy leadership of the SNP.
The MSP for Clackmannanshire and Dunblane, who also has responsibility for veterans, would automatically become deputy first minister of Scotland if elected by party members.
Mr Brown, who is driving forward the Aberdeen bypass and A9 dualling project, is making a statement “concerning the upcoming SNP internal elections” in Edinburgh this morning.
He is the first candidate to indicate he wants to replace Nicola Sturgeon, who is standing for the party leadership and post of first minister.
Meanwhile, the Conservatives have rounded on Finance Secretary John Swinney after he confirmed that the Scottish Government’s next legislative programme would be set out after the election of the next SNP leader at party conference in November.
The Tories are unhappy that there will be another period of inactivity in the Scottish Parliament which they say has been sidelined for months due to the independence referendum.
Party finance spokesman Gavin Brown said: “It is truly ridiculous that this period of a zombie government will now run well into November.
“Usually the first debate after the summer recess is the forthcoming programme for government, but this isn’t happening now for several months afterwards.
“We’ll also have the incredible position of the draft budget coming out in October, a month before the programme for government.”