Sir Keir Starmer has said the SNP leadership contest shows the party has “lost its way” with voters.
The Labour leader is hoping his party can capitalise on the moment and win over voters lost to the SNP in previous elections.
The campaign to replace Nicola Sturgeon as SNP leader and first minister has been hit by infighting as candidates take aim at each others’ government records and their social views.
Ash Regan, Kate Forbes and Humza Yousaf are in the race to replace Ms Sturgeon following her shock resignation last month, with the internal disputes spilling out during live TV debates.
Speaking to journalists on a visit to Siemens technology firm in Glasgow, Sir Keir said: “I think the SNP has lost its way.
“What you’re seeing now is a leadership contest in which the contestants are arguing about just how bad the SNP record is.
“At the moment, I think most people in Scotland are crying out for answers to the issues that they’re really facing.
“Yes, the SNP, I think, are falling apart. Yes, they’re focused on the wrong things.
“They’re having arguments with themselves but I am not complacent about this. I know we have to make our argument and earn every vote.”
He was joined by Scottish Labour leader Anas Sarwar and shadow chancellor Rachel Reeves as he made the case for putting Scotland at the heart of his economic growth plans.
Sir Keir said he did not have a preference on which candidate is elected.
He said: “I don’t mind who wins this candidates’ race in Scotland because what I see is candidates arguing about just how bad their record in Government is.
“I understand the desire of so many people in Scotland to have change.
“The change now is not whoever leads the SNP, the change now is a Labour government here in Scotland working positively for those changes in Scotland.”