In the upcoming byelection in Rutherglen and Hamilton West, Labour faces an altogether different battle from those fought recently in three English constituencies. Here, it confronts incoming on its exposed left flank in a firefight with the Scottish National party. Far from engaging in daily combat with English Tories and their press, Labour leaders parade their leftwing credentials in Scotland, without giving ammunition to the old blue enemy south of the border. Both the SNP and Labour desperately need a win. It would only take a 5% swing for Labour to unseat the SNP here; if it can’t, with all the brouhaha surrounding Nicola Sturgeon, her husband and police investigating party finances, hopes of capturing a tranche of crucial SNP seats at the general election will fade. But the first minister, Humza Yousaf, with low ratings and a quarrelsome party, will be urgently looking to shore up the SNP after 15 long years in power. Knuckle-dusters are out already. SNP leaflets in the constituency target Keir Starmer’s decision not to scrap the two-child benefit cap, suggesting there’s no difference between Starmer and Rishi Sunak. Labour ripostes that Rutherglen has been “failed by two sleaze-ridden governments and a shameless MP”: the former SNP MP, Margaret Ferrier, was ousted by a recall petition for travelling with Covid to London to speak in the Commons. The SNP boasts of its Scottish child payment, giving all families on universal credit an extra £25 a week per child. That’s in contrast to Starmer’s less-than-agile BBC interview in which, on the spur of the moment, he chose to prove Labour’s fiscal discipline rather than cancel the two-child cap affecting 1.5 million children. The two sides will fight over the recent claim that Labour has softened its radical workers’ rights plan. Angela Rayner was in Rutherglen with a forceful rebuttal: it’s just not so. Meeting apprentices in Glasgow, she promised that Labour’s new deal for working people would be law within 100 days of the party coming to power: “the biggest levelling up of workers’ rights in decades”. And so it is. It bans zero-hours contracts, and fire-and-rehire policies, makes the presumption of flexible working a day-one right, and strengthens parental leave and pregnancy protection. “We’ll make sure work actually pays with a genuine living wage that covers the cost of living,” Rayner has said. Ending bogus self-employment is “a key priority”. Pledging fair pay agreements that vary according to sector means some sectors that can afford it will have to pay a higher minimum. Trade unions will see their membership rise steeply when they are given access to recruit in every workplace. The issue that blew up last week concerned whether everyone would get rights from day one in a new job. Rayner said Labour would be “ending qualifying periods for basic rights, which currently leave working people waiting up to two years for basic protections”, with “stronger protections against unfair dismissal”. The claim is that Labour’s national policy forum weakened this with some permissible probationary periods for new employees: it caused a furore, with Unite and Momentum accusing Labour of kowtowing to employers, but Labour says a probationary period was always there. The GMB, Unison and all other affiliated unions have backed the policy. That’s because the rights that Rayner spelled out in Scotland are indeed radical. Labour expects this policy to come under the same relentless Tory attack at the election as introducing a minimum wage did in the 1997 campaign. Tory HQ has drawn up a list of 20 “anti-business” Labour policies, which it calls a job-killing “Trades Union Congress wish list”. Indeed, these rights were drawn up with strong backing from Frances O’Grady, the former TUC leader, and as Rayner told Glasgow apprentices, they would “raise living standards for all”, tilting power back towards employees. Is it because of a clumsy mishandling of messaging that Labour’s two most radical policies of recent years have now been tarred as “retreats”? Or is it Labour’s own ambivalence on whether to present them as radical or moderate? The £28bn pledged for Labour’s green investments – for jobs in clean energy, battery factories and home insulation – is enormous and popular. Tony Blair and Gordon Brown never dared make such a spending promise in 1997, even when the economy was growing, not stagflating, as it is now. It’s more money per capita than Joe Biden’s mighty green infrastructure fund. Taking two years to build up to this huge spend is reasonable: how do you get £28bn worth of spades in the ground, without waste, on day one? Yet Labour has let this delay enter the political lexicon as a green retreat. There are always doomsters eager to get disillusion with Labour in early, forever expecting betrayal. But Angela Rayner herself stands as guarantor for workers’ rights: it’s unlikely she would stand by and see those pledges seriously diminished. In the same way, Ed Miliband stands guard over Labour’s green credentials. But nor do I think Keir Starmer or Rachel Reeves has any less commitment to the radicalism of policies they drew up. Nerves and lack of self-confidence seem to make Labour hesitate to issue loud rebuttals when these “retreat” stories appear. They know the Tories’ well-oiled campaign machine (and its foghorn press) hasn’t yet got out its knife sharpener to begin assaulting Labour with utterly mendacious distortions of its policies. They know, despite an 18-point lead, that 55% of voters say they might still change their mind. They know that the party scoring best on the economy always wins. Labour has shifted that dial: entering No 10 last year, Sunak was most “trusted to run the economy” by 33% to Starmer’s 29%, according to Opinium. Though Labour now leads on the economy by six percentage points, that still feels precarious. Fighting to win Rutherglen against an SNP foe purporting to be more leftwing is doing Labour good. As he travels up and down to Scotland almost monthly, do read Starmer’s thundering essay in the Scotsman, full of words Blair and Brown feared to use. “In the recent past,” he wrote, “Labour was afraid to speak the language of class at all – but not my Labour party. No, for me, smashing the ‘class ceiling’ that holds working people back is our defining purpose … Because you cannot seriously take on inequality or poverty … without talking about class. This is personal.” On poverty, he wrote, “This isn’t the trickle-down Tory nonsense that, for working-class communities, means jobs trickle out and power trickles up … I don’t look at our current social security system and think tinkering at the edges will be good enough.” And he repeats Rayner’s list of “a new deal that will strengthen workers’ rights and finally make work pay”. Expect this to be the mood of Labour’s October conference: messages get clearer as elections approach. As ever, Labour will do more in office than would be wise to promise in advance, but that requires some trust and patience from its natural supporters. Polly Toynbee is a Guardian columnist