The Deputy First Minister has failed to explicitly commit to reinstating universal child benefit in an independent Scotland.
Nicola Sturgeon said the SNP's commitment to "universal provision of key benefits" would be part of its policies but did not give specific assurances on child benefit, which became means-tested earlier this month.
Households where one partner earns at least £50,000 will now have their child benefit payments clawed back as part of an overhaul to the UK welfare system. During a debate on the issue at Holyrood, Ms Sturgeon described the move by the UK Government as "fundamentally wrong".
She said: "With child benefit there is a more fundamental point at stake, a fundamental point of principle. I believe that it is fundamentally wrong that it is now subject to a means-test."
Conservative MSP Liz Smith intervened, asking: "When you outline your policies for an independent Scotland, are you saying that there will be a commitment to reinstate universal child benefit?"
Ms Sturgeon replied: "Well, we will outline our policy for welfare in an independent Scotland and we'll do that in order to persuade people of the benefits of independence.
"Can I say that our commitment to universal provision of key benefits will be a key part of those policies. And it will also be our aim over time, when we have our hands on the levers of power in an independent Scotland, to ensure we build a welfare system that reflects our values as a society."
Changes to child benefit, which the Deputy First Minister said will push 15,000 Scottish children into poverty, were also criticised by Labour's Drew Smith. But he warned against Ms Sturgeon's claims that independence is the answer.
He said: "We are also wary of the promises of parties who have never had to administer a welfare system promising the earth."
Liberal Democrat leader Willie Rennie said the SNP focuses too much on the UK Government. "Always from a lofty position they complain, they commentate, but they rarely provide solutions which, I think everyone would admit, is a tough task," he added.