The former first minister announced his return to frontline politics as leader of the Alba Party on Friday in an effort to gain a “super majority” for independence at Holyrood.
But Mr Sarwar questioned his motives, as the rift between the former and current first ministers grows wider after Mr Salmond alleged that senior members of the SNP had engaged in a concerted effort to remove him from public life.
Speaking to journalists on Wednesday, Mr Sarwar was asked if the former first minister was attempting to “game the system”.
He replied: “I think it’s worse than that.
“I think he’s pretending this is about a referendum and he is pretending this is about trying to gain an advantage and game the system, but what he’s interested in is revenge, not recovery.
“I think this election campaign, the circus we’ve seen in the last few days, we cannot allow that to be the circus of the next six weeks and we can’t allow that to be the circus of the next five years of our Parliament.
“Scotland deserves so much better than that and we can’t allow SNP infighting, egos, settling of scores or going back to the old arguments to distract us from what is the biggest challenge of our lifetime.
“If you’re wanting to put the national interest first, if you want to put people, their families and our national recovery first, you’ve got to have a Parliament that demonstrates that.
“That is my relentless focus in this campaign and why I’m encouraging people to vote Labour in this election.”
Mr Salmond’s Alba Party has announced it will only stand in regional seats, in the hope that the SNP will have enough for a majority purely in constituencies.
The former first minister is standing on the North East regional list, while MPs Neale Hanvey and Kenny MacAskill announced they are switching to Alba from the SNP and standing on May 6.
Former SNP MP George Kerevan also defected on Tuesday, although it is not yet clear if he plans to stand for election.