Scottish Labour leader Anas Sarwar will say his party can beat the SNP in seats “across Scotland” at the next general election.
He will address Labour’s conference in Liverpool on Monday, where he will hail his party’s win in the Rutherglen and Hamilton West by-election.
Michael Shanks exceeded expectations and took 58% of the vote at the by-election count in South Lanarkshire on Thursday night.
It led polling experts to believe that Labour could return to being the largest party north of the border, potentially opening the door to Downing Street if there is a similar swing at the next general election.
Mr Sarwar will say his SNP opponents have chosen to “blame the voters” for their loss.
He will tell delegates: “Now no SNP MP can sit safely, taking their communities for granted as so many have.
“So I say to Humza Yousaf: This isn’t about swings or the polls – this is about putting the people of Scotland first.
“And because you won’t do that – we can beat you across Scotland.
“Every community in Scotland now has the chance to choose change with Scottish Labour.”
SNP deputy leader Keith Brown said: “Labour’s Scottish branch office can’t be trusted to stand up for the people of Scotland and will only answer to Sir Keir Starmer, who is abandoning all principles to get his hands on the keys to Downing Street.
“The people of Scotland deserve better than Sir Keir Starmer’s pro-austerity, pro-Brexit offering of the Tory status quo.
“At the general election, the SNP offers an opportunity to escape the chaos of Westminster.
“Independent European countries similar to Scotland are both wealthier and fairer than the UK. With the abundance of resources and talents that we have, why not Scotland?”