The full rollout of a benefit payment to low-income families in Scotland has been hailed as a “watershed moment” – with politicians in the rest of the UK being urged to “take notice”.

Some 400,000 children in Scotland are now thought to be eligible for the Scottish Child Payment, and the Joseph Rowntree Foundation said if the scheme was replicated across the rest of the UK, 5.3 million youngsters in England, Wales and Northern Ireland could benefit.

Chris Birt, associate director for the think tank in Scotland, said the benefit should show the UK Government that “prioritising those on low incomes is possible”.

It also shows other devolved governments that the “constraints” on their powers are “no barrier to compassionate and significant action to support families”, he added.

The Scottish Child Payment was previously paid to low-income families with younger children but is now available to all eligible households with youngsters under the age of 16.

At the same time, the payment – hailed by First Minster Nicola Sturgeon as the “most ambitious child poverty reduction measure in the UK” – has now been increased from £20 a week per child to £25.

It means eligible families will receive £1,300 a year per child – which Mr Birt described as a “welcome boost” at time when many household budgets are “stretched to breaking point”.

He said: “The full rollout of the Scottish Child Payment is a watershed moment for tackling poverty in Scotland, and the rest of the UK should take notice.

“At £1,300 per child, per year it will be a welcome boost to family budgets that are stretched to breaking point already.

“No child should live in poverty so there is clearly more to do, but the Scottish Government should be commended for prioritising spend on this vital measure at this time.

“But this is not just a cost-of-living crisis measure, it is an enduring investment in our children.”

He acknowledged governments face “difficult financial decisions at the moment”, but said these are “nothing compared to the impossible choices that families across the UK face in this crisis”.

Mr Birt continued: “A country as wealthy as the UK can do much, much better and the Scottish Government’s action shows the UK Chancellor that prioritising those on low incomes is possible.

“It also shows the other devolved administrations that constraints on powers and financial flexibility are no barrier to compassionate and significant action to support families.”

MSP Ben Macpherson, Holyrood’s minister for social security, said the benefit would lift as many as 50,000 children out of poverty and hailed it as a “game-changing anti-poverty measure”.

“This benefit is going to provide a significant financial uplift for households who are struggling, and that’s £1,300 per child extra from the Scottish Child Payment that families who are eligible will be getting that’s not available elsewhere in the UK,” he told the BBC’s Good Morning Scotland on Monday.

One mother, identified only as Laura, said the payment will help with the cost of feeding her family and heating their home.

She will receive the payment for her 10-year-old and her 14-year-old, saying the £200 extra every four weeks “really is the difference between heating and eating”.

She said: “I’ll be able to put extra gas in the meter for heating and hot water and extra food in the cupboards.

“My kids, especially my two teenage boys, won’t be feeling hungry as often and I’ll be able to make the house warm for them coming in from school, which is a really great feeling.

“I feel so helpless and feel like a failure when they’re hungry or cold and now I’ll be able to give them what they need a bit more often. It’s a huge relief and takes away some anxiety and stress.”

The charity One Parent Families Scotland also urged the UK Government to follow the Scottish Government’s example.

Chief executive Satwat Rehman said: “With rising costs and falling temperatures, this winter will be particularly challenging for families on a low income.

“The increase in financial support via the new Scottish Child Payment and its availability to parents and carers of older children will provide a much-needed lifeline to families on a low income.

“We hope the UK Government will follow suit and provide further support to low-income families in its upcoming autumn budget on Thursday.”

John Dickie, director of Child Poverty Action Group (CPAG) in Scotland also made a similar plea, telling politicians at Westminster: “If the Scottish government can make this kind of serious investment in protecting our children from poverty then so too can the UK Government.

“The Autumn Statement is the Chancellor’s opportunity to not only ensure UK benefits rise in line with inflation but to reverse the cuts made since 2010 – starting with a £20 a week uplift to child benefit.”

The UK Government noted its expansion of free school meals in England and other support available via Universal Credit.

A UK Government spokeswoman said: “Our priority will always be to support the most vulnerable and we recognise that people are struggling with rising prices, which is why we are protecting millions of those most in need with at least £1,200 of direct payments.

“In addition, vulnerable families are being supported by the Government’s household support fund – which was boosted by £500 million – to help pay for essentials and latest figures show that there were 200,000 fewer children in absolute poverty after housing costs compared to 2019/20.

“The UK Government has also provided an extra £123 million for the Scottish Government to help vulnerable families at their discretion and this is in addition to the significant welfare powers they already have.”