The Scottish National party and Scottish Labour are both claiming they are the only party capable of addressing the cost of living crisis that is overwhelming voters, as campaigning begins in earnest in the Rutherglen and Hamilton West byelection. The contest in the central belt swing seat, which is seen as a crucial test for both parties, started on Tuesday after constituents voted for the Covid rule-breaking MP Margaret Ferrier to be removed from her seat. Drawing early battle lines as he visited a community development trust alongside the SNP candidate, Katy Loudon, on Wednesday morning, the SNP leader and first minister, Humza Yousaf, said voters faced a “stark choice”. “You can either vote for an excellent SNP MP who will stand up for them and stand up for Scotland, or they can have a Labour MP that will do Keir Starmer’s bidding and back cruel Tory policies, which have seen tens of thousands of children, many of them in this very constituency, plunged into poverty.” Yousaf said it was “simply not good enough” for the Scottish Labour candidate, Michael Shanks, who was officially launching his own campaign several streets away, to insist he would campaign and vote against the two-child benefit cap – which the UK Labour leader has said he would not immediately scrap if elected, despite an outcry from anti-poverty groups and some of his own MPs. But Shanks, who likewise takes a different position on gender recognition reform from UK Labour, backing Scottish Labour’s stance on de-medicalisation, said these were examples of “the maturity of devolution”. “The SNP want to make this byelection all about divisions in Labour because they’ve got nothing to offer themselves,” he said. He added: “The same tired lines about independence being the only change on the table just don’t work any more.” Shanks said he had already knocked on 20,000 doors across the constituency and the local community was desperate for “a fresh start” after years of limbo with Margaret Ferrier, who continued to sit as an independent. She was expelled from the SNP after it emerged in 2020 that she had travelled to London and spoken in the Commons while awaiting the result of a Covid test, then taken a train back to Glasgow after a positive result. Shanks said that many constituents remained “absolutely furious” about Ferrier’s conduct, and that he had met “huge numbers” of previous SNP voters who were now considering Labour. He argued that supporting independence in the longer term “doesn’t stop people voting for us on all the other issues that are important to people”. But Yousaf said that the message he and Loudon would be taking to voters was that “independence is the only escape”. “Independence is needed now more than ever because you don’t just have a Tory party that’s inflicting harm but Keir Starmer, a prospective prime minister, who’s saying he would keep many of those same cruel policies in place.” When asked if she was concerned that the ongoing police investigation into SNP finances would overshadow her campaign, Loudon said: “It’s not an ideal situation, and I don’t think there’s any point in saying otherwise. I do have to say genuinely when we have been out chapping doors that is not what people are talking about. Just now people are deeply concerned about the cost of living crisis.” As Labour continued to press the SNP, which is responsible for moving the writ to hold the byelection, to hold it on 5 October, the earliest possible date after the Commons returns from its summer recess, Yousaf said he would “absolutely” commit to that date, adding: “We’ll do everything in our gift to get this byelection as early as possible.”