Mr Sarwar pointed to analysis that shows that a £40 per week Scottish Child Payment would lead to child poverty reduction targets being met with to up to 80,000 children being lifted out of poverty – slashing child poverty by nearly a third in one move.
However he said that child poverty in Scotland has been rising and currently sits at 26% - equivalent to one in four children.
And he is now calling for that £20 sum to be doubled immediately in a move that's been backed in recent weeks by over 100 leading poverty organisations and faith groups in an open letter to the First Minister who has said she wants the driving mission of the Parliament to be ending child poverty.
Mr Sarwar said: “It simply beggars belief that the SNP doesn’t seem to recognise the urgency.
"We need to listen to the urgent calls and double the Scottish Child Payment and commit to doubling it again the following year.
"This simple act would cut child poverty by nearly a third, transforming 80,000 lives.”
Central Scotland List MSP Mark Griffin, who joined Mr Sarwar on the campaign trail, added: “The SNP have been far too timid for far too long and it’s time they took radical action to tackle the scandal of child poverty.”
Labour Councillor Allan Graham added: “This is absolutely the right call and would make such a big difference to lots of families in my ward.”
However Scottish Nationalist MSP Jamie Hepburn said: "At the election we stood on a platform of doubling the value of the payment in this Parliamentary term and that’s what we will do, recognising the need to go further.
“Of course this payment is largely about mitigating the worst impacts of negative reforms to the social security system by the Tory UK Government.
"If we were independent then Scotland could do much more than just mitigate these cuts. Anas Sarwar’s crocodile tears over cuts to Universal Credit ring a little hollow when we remember he supports powers over social security remaining in the UK Government’s hands.”