Former prime minister Gordon Brown will insist there is an urgent need for ministers at Holyrood and Westminster to work together to tackle poverty, as a new poll found more than half of Scots think wrangling over the constitution has left the country "stuck in a rut".

A poll for Our Scottish Future, the think tank set up by Mr Brown, found 53% of people questioned agree that after a "decade of constitutional debate, Scotland now feels stuck in a rut" - with only 10% disagreeing with this.

Mr Brown will tell an event at the Edinburgh International Book Festival on Wednesday that rows between the SNP Government in Edinburgh and the Conservative administration in London have turned politics into a "Punch and Judy show".

He will claim the disputes are "trapping us in negativity and pessimism", insisting what is needed instead is politicians working together to tackle poverty.

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Experts at the Joseph Rowntree Foundation are expected to confirm in the autumn that the number of people in "destitution", with a very low income and only limited access to essentials such as food, heating and basic toiletries - has "virtually doubled over recent years", Mr Brown will say.

That is since a 52% rise in households in destitution between 2017 and 2019.

Mr Brown will say: "Today, over one million - 1,110,000 - Scots, or 21% of Scotland's population, are in poverty, including 250,000 children.

"The vast majority of those children are living in working households where breadwinners simply don't earn enough to make ends meet.

"We are now seeing poverty that I never thought I'd see again, with worrying episodes of rickets, malnutrition and destitution and a failure to tackle it head on with co-operation between the two governments.

"That is why I say to UK and Scottish ministers that it is time to agree on the urgent need to co-operate in the interests of solving poverty, rather than a stand-off that helps no-one."

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The former Labour leader will argue that rather than having a separate body for welfare payments north of the border, Social Security Scotland, "a better solution would be to co-operate... using a single system, with one computer, one application system, one check system, and one payment and audit system".

Setting up a separate Scottish benefits body was the result of "a toxic combination of Scottish ultra-go-it-alone nationalism and British gross negligence", Mr Brown will say.

He will claim that the current system "allows escalating levels of poverty to continue through working on separate solutions without saving money by co-operating".

Estimates suggest, the former PM will say, the "duplication of two systems has meant that we could have paid the families of 250,000 poor children around £2,000 each", which he will say would be a "better way of relieving poverty rather than funding an expensive bureaucracy".