Image copyright AP

More than a million benefits claimants may be facing destitution after disappearing from the welfare system, Labour ex-minister Frank Field claims.

Sanctions are being applied "at a scale unknown since the Second World War" and the fate of at least a third of those hit "is anybody's guess", he said.

He says a government survey is needed to track the whereabouts of those dropping off the roll.

But the Department of Work and Pensions says the claims have "no basis".

About 1.5 million people leave the welfare system each year, but it is unclear how many are left without work or benefit payments, according to Mr Field, who chairs the influential Commons Work and Pensions select committee.

Yellow card

Some may be in jail or have moved abroad, while others are people on benefits who have been hit by sanctions and dropped out of the system, a report co-authored by Mr Field and Andrew Forsey, head of the MP's parliamentary office, found.

Sanctions are imposed when claimants fail to comply with welfare conditions imposed by the government.

The report, to be published on Monday by think tank Civitas, calls for ministers to carry out an urgent survey to find out what happens to claimants expelled from the welfare rolls who appear not to find work.

Image copyright PA Image caption Frank Field was tasked with "thinking the unthinkable" as a welfare reform minister in 1997

It welcomes plans to trial a "yellow card" early warning system for claimants facing sanction because they are deemed not to have done enough to find work - and calls for Jobcentre Plus staff to be given powers to issue non-financial sanctions.

It also recommends the Department for Work and Pensions trials a "grace period" for vulnerable claimants that eases the rules at times when they are facing transition or acute difficulty.

Mr Field and Mr Forsey said: "The number of sanctions was halved in the year leading up to the 2015 election, but it still remained at half a million.

"Sanctions are therefore being applied at a scale unknown since the Second World War, and the operation of sanctions on this scale makes for a most significant change in the social security system as it has existed in the post-war period.

"A number of people - we know not how large a number - are being totally disconnected from both work and welfare, and risk being exposed to destitution.

"Justice calls for a major survey of what happens to the hundreds of thousands of people thrown off the welfare rolls each year through the sanctioning process.

"It is unacceptable, not only for this government, but for its predecessor and those who will follow, to take away benefit from a mass of people each year and not trouble themselves with how this army of people survive.

"For that is what is happening under the government's sanctions policy. The ability to track the well-being of the whole population is now a part of being a grown up government, let alone a 'One Nation' government."

'Record employment'

But a Department for Work and Pensions spokesman said: "There is no basis to these claims.

"People leave the benefits system for many reasons, including when they go to work - which is good news.

"It's extremely unlikely anyone would leave the benefit system because of a sanction. The truth is we have record employment and we spend £80bn supporting millions of people who are unemployed or on low incomes."

In 1997, Prime Minister Tony Blair gave Mr Field the task of "thinking the unthinkable" as a welfare reform minister, but he later resigned from government.

Following the 2010 general election, he led an independent review into UK poverty for the coalition government.

Last year Mr Field co-chaired the All-Party Parliamentary Inquiry into Hunger in the UK.