Anas Sarwar has insisted that the choice for voters in Scotland is now between a “bitter, angry, divisive” SNP and a “future-looking” Labour Party.
It comes after the party made gains in the local elections across the UK, with Scottish Labour adding 20 councillors to take their total number in the country to 282.
The SNP remain as the largest party in the country, having gained 22 seats to take their tally to 453.
Meanwhile, the Scottish Conservatives had a difficult election, losing 63 councillors across Scotland to take their overall total to 214.
The gains for Scottish Labour were celebrated by the party, with Labour leader Keir Starmer joining Sarwar in West Dunbartonshire on Saturday.
But, the SNP’s Westminster leader Ian Blackford compared Scottish Labour and the Scottish Conservatives to “two bald men fighting over a comb”, with the SNP having won their 11th successive election.
Sarwar, however, insists that his party are now aiming to challenge the SNP for power at Holyrood.
“It’s great to be in second place, it’s great to have Scottish Labour back, but let’s be very clear – we don’t aspire for second place, we aspire for first place,” he told the BBC on Sunday.
“If you look at where we were 14 months ago, 14 months ago we were at 14% in the opinion polls, we had to stop Armageddon last year at the Scottish Parliament election.
“And over the course of the last year, we have built our support to get into a strong second place.
“But we’re not looking in the rear view mirror back at Douglas Ross now, we’re looking (with) our eyes firmly set on the SNP and to try and compete in the next Scottish Parliament election.”
Sarwar made the case for Scottish Labour, whilst acknowledging the challenge ahead for the party.
He said: “I recognise we’ve got a mountain to climb, I recognise there’s a tough task ahead, but the choice in Scotland is now clear.
“The choice in Scotland is now not between a bitter, nasty, backward-looking Conservative Party and the SNP.
“The choice in Scotland now is between a bitter, angry, divisive, growing more and more out of touch and arrogant every day SNP, versus a future-looking, positive, unified Labour Party.
“That’s the choice now in Scotland.”
The Scottish Labour leader also ruled out the prospect of his party entering into any formal coalitions on councils across Scotland.
“I made clear throughout the election campaign that we would be having no formal coalitions with any other political parties, that’s a position that remains,” he said.
“Yes, it’s great we have majority control of West Dunbartonshire but we’ll be looking to seek to form minority administrations in other parts of the country.
“And where we can’t form minority administrations, we will oppose the decimation of all these communities that’s happening because of SNP cuts.”
He added: “What we’ve said is there will be no formal coalitions, but on individual issues where we get cross-party support on individual issues that matter to local people, then we’re willing to work with individual councillors and individual political parties.
“But no formal coalitions.”
The Scottish Labour leader also said that the next general election will not be a case of “Scotland versus England”.
“I think one of the big challenges we’ve had is for 15 years, the SNP have had it all their own way,” he said.
“They’ve had a Labour Party that’s been on the canvas and they’ve had an opposition in the Conservative Party that it’s been easy for them to point and say, ‘look at the disaster that is the Conservative Party, let’s get away from that’.
“That frame has now fundamentally shifted in Scotland.”
Sarwar added: “The next electoral contest in Scotland is going to be the general election.
“And Nicola Sturgeon is going to pretend between now and the general election that it’s Scotland versus England.
“It’s not Scotland versus England. If you look at Birmingham, Liverpool, Manchester, London, Cardiff, Glasgow, Edinburgh, right across the country people are angry and fed up with this Conservative government.
“It’s not Scotland versus England, it will be Boris versus Britain and Britain’s going to win.”