A mental health crisis means the number of working age Britons classed as disabled has surged to one in four.

Some 9.8 million people aged 16 to 64 are disabled, which is up by 1.5 million from pre-pandemic levels, according to figures from the Department for Work and Pensions (DWP).

Details were revealed at the same time as the Institute for Fiscal Studies (IFS) estimated that the taxpayer’s bill for working age health-related benefits will rise by £15 billion to £63 billion by 2028-29.

The new Labour government announced efforts to tackle the rise in the benefits bill in the Budget, including the adoption of workplace assessments which are expected to reduce the number of claimants by 500,000.

Separately, new DWP fraud squads are being established while the bank accounts of claimants may be scrutinised where there are suspicions of bogus claims.

The DWP said the bulging disabled workforce is “associated with an increase in people reporting mental health conditions”.

Diagnoses doubled in the past decade, with 2.5 million people of working age now reporting a mental health condition, compared with 1.2 million in 2013-14.

Depression, bad nerves or anxiety diagnoses have also surged from 826,000 to 1.7 million in the same timeframe.

Eduin Latimer, of the IFS, said the impact of the pandemic is a driving force behind the surge in disabilities.

He said: “The pandemic is a key factor, but it isn’t the only one. The NHS has struggled with waiting lists and providing care, potentially giving rise to the number of disabled people.

“The rise isn’t a UK phenomenon, but we’ve seen a sharper increase here than other European countries have, so it suggests it’s more than just the pandemic alone.”

In the past 10 years, there has been a huge 86 percent increase in the number of young people aged 16 to 34 classed as disabled.

Looking beyond mental health conditions, the figures show the number of diagnosed musculoskeletal conditions – which include disabilities in arms, hands, legs, feet, back or neck – has remained mostly unchanged since 2013-14.

The DWP said the dramatic increases in claims, particularly around mental health, “could be due to several factors, including changes in public awareness and attitudes towards disability”.

It also suggests that behavioural changes in society over diet and levels of physical activity could have an impact.

Ten years ago, 11.7 million said they had a long-term health problem, but that number now stands at 15.1 million. In total, 23 percent of Britain’s working-age population are disabled, while 36 percent report having a long-term health condition.

The Health Foundation think tank projects the number of people in England living with major illness is expected to increase by 37 percent by 2040 – nine times the rate at which the working age population is expected to grow.

Currently, 4.1 million working-age disabled people are unemployed, a 260,000 increase on last year.

DWP figures show that 21 percent of economically inactive disabled people want a job, compared with just 14pc of non-disabled people.

Linda Burnip, co-founder of Disabled People Against Cuts, said there are too many barriers preventing people from getting a job.

She told the Telegraph: “It’s hardly surprising that more disabled people are unable to work.

“This is after 14 years of austerity, loss of mental health services and treatments, rocketing waiting lists, increased poverty, and homelessness.

“The policies of the new Labour Government so far have only led to increasing levels of despair that nothing will change for the better for anyone on low income of any kind.”

Rachel Reeves pledged in her maiden Budget that she would honour the Conservatives’ proposals to slash £3bn from the welfare bill by tightening access to sickness benefits.

A DWP spokesman said: “The work capability assessment is not working. It needs to be reformed or replaced as part of a proper plan to genuinely support disabled people into work – bringing down the benefits bill and ensuring we continue to deliver the savings set out by the previous government.

“But these changes shouldn’t be made in haste. That’s why we’re taking the time to review this before setting out our next steps.

“Too many people have been denied the support they need to progress – that’s why our Get Britain Working Plan will deliver the joined-up health and skills support they need to return to work and stay in work.”