Former health secretary Alex Neil has urged Humza Yousaf to take steps to reunite the SNP after its by-election hammering last week.
The party veteran says Kate Forbes must be offered the job of deputy first minister as part of a radical overhaul to avoid “doomsday” at the next general election.
A 20.4% swing to Labour saw Michael Shanks secure 17,845 votes – more than double the number polled by the SNP’s Katy Loudon.
Mr Neil wants to see Ms Forbes brought back into the fold and the Greens kicked out of government in favour of ministers “who can actually do the job”.
Ms Forbes was dropped as the SNP’s finance chief earlier this year after being defeated by Mr Yousaf in the race to replace Nicola Sturgeon as leader.
Mr Neil said: “My thoughts all along were that we were going to take quite a hammering, and unfortunately that has been the case.
“My view is that this cannot just be treated lightly. I think we now very clearly need urgent action by the leadership to overhaul both policies and personnel, and I think Humza should have a cabinet reshuffle and bring in Kate Forbes as the deputy first minister and finance minister.
“He needs to bring more talent into the cabinet, people who are more experienced and who can do the job.”
Mr Neil, who is regarded as an SNP stalwart, is one of a number of big names who are planning to stay away from the party’s conference in Aberdeen later this month.
He is not calling for Yousaf to be replaced as leader but warns swift action is needed.
“What we need is radical change – not Mr Continuity,” Neil said.
“I believe the situation can be turned round and we don’t need to be facing doomsday next year if we get our act together and get it together quickly.”
Mr Yousaf said the party will reflect, regroup and come back stronger.