Church leaders have joined anti-poverty campaigners in calling on the Scottish government to use new welfarepowers to increase child benefit by £5 amid growing fears for children living in the worst social conditions, The Scotsman reported.

The Scottish Labour leader Kezia Dugdale also backed the call, insisting that her party would support such a move at Holyrood where the new post-referendum powers allow ministers to top up existing UK benefits.

But last night, the Scottish social security secretary Angela Constance appeared to rule out such a move, warning that it would cost £250 million and would not target youngsters in poverty effectively.

William Nolan, the Bishop of Galloway, who is president of the Catholic Church's justice and peace commission, announced support for the Give Me Five campaign yesterday.

With more than 260,000 children in Scotland growing up in families struggling to make ends meet, supporters argue that a £5 increase in child benefit could remove some 30,000 children from poverty.

Bishop Nolan said: 'For a growing number of children, this is not the Scotland of equality, fairness and opportunity that our politicians tell us they wish to achieve. I would urge politicians of all parties to support this initiative and act now to reduce the number of our children for whom poverty is destroying their childhood and stifling their future.'

Meanwhile Dr Derek Browning, the moderator of the General Assembly of the Church of Scotland, said there was a 'political, social and moral imperative that we act now to effect change for the good,' adding: 'The Church of Scotland stands alongside people of all faith traditions, and none, in the move towards fairness for all our children.'

Polling by Survation has found that almost two-thirds of Scots are in favour of Holyrood increasing child benefits, with 36.2 per cent strongly supporting the move while 28.6 per cent saying they were 'somewhat' in favour.