The SNP has accused Sir Keir Starmer of sending a “shiver along his frontbench” over the plan to uphold the two-child benefit cap.
It came as the Scottish party produced mugs claiming Labour’s policy was “made in China” and asking: “What’s the point of Labour?”
Earlier Rachel Reeves hit back at Labour MPs critical of the plan to uphold the Tories’ “nasty” two-child cap.
The shadow chancellor said that “dire” public finances meant there was not enough money to ditch the policy, despite the fury it has elicited from both the left and normally supportive backbenchers.
SNP Westminster leader Stephen Flynn attacked Sir Keir at PMQs in the Commons, saying he could see a “shiver running along the Labour frontbench right now, looking for a spine”.
He added: “Voters in Scotland are used to child poverty under the Tories, they almost expect it. But what they don’t expect is child poverty support from the Labour Party.”
Ms Reeves told BBC Radio 4’s Today programme that the “sad truth” is that there were lots of Tory policies a Labour government would not reverse.
Sir Keir Starmer defended making “tough decisions” during an interview with Tony Blair on Tuesday night – mentioning six other policies Labour government could not afford.
Asked about his remarks, Ms Reeves told the programme: “There are more than six things that an incoming Labour government won’t be able to do.”
The shadow chancellor said: “We are going to have the most dire economic inheritance of any incoming government. The level of debt in the UK economy is the same size of everything we produce in the economy on an annual basis.”
She added: “I’ve lost count of the number of times I’ve gone through the division lobbies and vote against what the government have done. Does that mean we’re going to be able to reverse all of those things? The sad truth is we’re not going to be able to do that because of the dire economic inheritance.”
She also refused to say if Labour would scrap the controversial bedroom tax, introduced by George Osborne. “We’ll set out all of our plans around benefits and taxation and other spending closer to the general election.”
Keir Starmer and Labour’s shadow chancellor Rachel Reeves
She added: “It is our duty to get control of the public finances and ensure we’ve got a stable economy. It’s not a nice-to-have. It is the rock of stability upon which all our policies are built. There will be nothing in a Labour manifesto that is not fully costed.”
The phrase ‘Sir Kid Starver’ has been trending on Twitter, while Scottish Labour leader Anas Sarwar and MPs from different wings have spoken out against the “terrible” decision.
The row is set to explode again at Labour’s National Policy Forum meeting this weekend, where party figures will meet in Nottingham to form a programme ahead of next year’s general election.
But a former Bank of England economist Tony Yates said Labour’s claim that there was “no money left” was “false”. And Jonathan Portes, professor of economics King’s College London, told The Independent that the claim was “laughable”.
Asked what the point of a Labour government Ms Reeves told Today her party would expand the windfall tax, scrap non-dom tax status and free breakfast clubs in all primary schools. “My over ambition is to grow the economy … to get the money we desperately need.”
