The SNP has attacked the Conservative- Liberal Democrat Coalition over figures which suggest more Scottish children at risk of living in poverty.
Scottish ministers said that the blame lay with the Coalition Government's welfare cuts, which have seen billions of pounds taken out of social security.
The Coalition argue that reform of welfare system is necessary to free those trapped for a lifetime on benefits.
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The SNP pointed to estimates from the charity Shelter that 4,000 children in Scotland were homeless this Christmas.
The Child Poverty Action Group has also predicted that by 2020 up to 100,000 extra children will live in poverty in Scotland, largely as a result of tax and welfare changes.
The Conservative chancellor George Osborne has outlined plans for further cuts to in-work benefits if his party wins next year's general election.
But the Liberal Democrats and Labour have both condemned that approach and each suggested a slower path to reducing the UK's deficit that would also see the rich taxed more.
More than 60 charities and other organisations have called for the full devolution of welfare policy to Scotland.
But opponents argue that parts of the issue are better dealt with at a UK-wide level.
SNP Work and Pensions spokesperson Dr Eilidh Whiteford MP said: "Too many children in Scotland will be living in poverty this Christmas and too many working families will be struggling to put food on the table and heat their home.
"Poverty in Scotland is being perpetuated by UK Government policies and the powers we need to tackle this problem - such as working tax credits and child benefit - will remain in the grip of Westminster."
Extra powers on welfare have been promised to Scotland as part of the Smith Commission proposals on greater devolution.
All of the pro-Union parties have signed up to implementing the agreed settlement no matter who wins in 2015.
However, while Labour have pledged to bring forward the proposals in the first Queen's speech after the election, the Tories have made no such commitment.