Suella Braverman wants to help lift children out of poverty by scrapping one of her party’s harshest welfare policies. Yes, I do mean that Suella Braverman; and no, I can’t quite believe I’m typing these words either. Then again, who thought Natalie Elphicke would ever defect to Labour? Sometimes lions really do lie down with lambs, though you can see why lambs tend to have very mixed feelings about it. Anyway, writing in the not exactly bleeding heart Sunday Telegraph, Braverman unexpectedly joined a long line of children’s charities and expert reports who have been pointing out for almost seven years now that the two-child benefits limit – which prevents families claiming tax credits or universal credit for a third or subsequent child born after 2017 – is plunging ever more families into desperate circumstances while failing to achieve what its author George Osborne said it would, which is incentivise work. This is because 59% of families affected have at least one partner working already, and their problem is mostly that they’re not actually paid enough to survive on work alone. As for making poorer parents think twice about having children, plenty of people either don’t realise they’ll be caught by it until too late, or get pregnant in good times only to endure an unexpected run of subsequent bad luck. What the policy definitely has done, however, is help ensure that 43% of families with three or more children are now living in poverty. It’s not just cruel but hopelessly ineffective on its own terms, and pretty much everyone in the Labour party knows it. How galling, then, to find themselves lectured from the moral high ground not just by Braverman but by Scotland’s brand new first minister, John Swinney, who renewed calls for a future Labour government to scrap the limit within days of being appointed. The trouble with outflanking the Tories to the right as boldly as Keir Starmer has done is that it leaves his party defending a frankly implausible swathe of political territory, and not just from an attack by the left. In his wildest dreams Starmer presumably didn’t imagine someone like Braverman taking advantage of his exposed flank, any more than Labour MPs imagined having to defend a loose cannon like Elphicke against everything her former Tory colleagues can throw at her. But as confusing as all this shaking of the political kaleidoscope is, it does throw up some intriguing opportunities. Scrapping the two-child limit would take almost half a million children out of poverty, at a cost of about £2.5bn by 2024-25. It’s money that the shadow chancellor, Rachel Reeves, doesn’t currently have, but then she doesn’t have the money to raise defence spending to 2.5% of GDP either yet, and Labour is nonetheless promising to do that as soon as funds allow. In both cases, cutting corners now could cost this country dearly in future. Though tackling child poverty is expensive, not tackling something with profound lifelong implications for health, education, employment and welfare is likely to cost billions more over the long term. Frankly, I’d be amazed if a future Labour government didn’t end up spending some of the proceeds of that future growth it keeps promising on alleviating poverty, just as it did when last in power. So why not say something more explicit? The crude answer is that the two-child limit remains bizarrely popular, with 60% of voters polled by YouGov last summer keen to keep it. What makes Braverman’s intervention interesting, however, is that together with Swinney’s it shows how an otherwise wildly improbable coalition for changing minds may emerge. Of the two, Swinney represents the more serious threat to a Labour party that badly needs to win back seats in Scotland. By promising to eradicate child poverty, just as Gordon Brown once did, the SNP is reminding potential defectors to Labour of a radical edge they sense is still missing under Starmer. Braverman, by contrast, is more closely allied with rightwing pro-natalist Tory MPs who see falling birthrates as an existential threat to the west’s survival, and want the welfare state reengineered to support bigger families rather than discouraging them. This is where lions and lambs generally part company, of course: few in the Labour party would be comfortable fighting this particular corner with her. But it’s not impossible to see a future Labour government finding itself awkwardly squeezed on the two-child policy between a hard-right culture war party led by someone like Braverman and its own disappointed critics on the left, over a position many Labour MPs already feel deeply uncomfortable defending. There’s one obvious way out of that. How lucky for Labour that it happens to be the morally conscionable thing to do. Gaby Hinsliff is a Guardian columnist