Labour is under fire for refusing to reveal how many people will be hit by new benefit rules announced this week. The changes make it harder to claim Personal Independence Payments, which are provided to help disabled and long-term ill people with living expenses. Cuts announced by Work and Pensions Secretary Liz Kendall mean more claims will be refused but the Government is to reveal how many on March 26 – the same day that Chancellor Rachel Reeves delivers a financial statement which will dominate events at Westminster.

Charities today criticised the delay releasing full details of the impact of cuts. James Taylor, executive director of strategy at disability equality charity Scope, said: “These are the biggest cuts to disability benefits on record, and their impact is highly likely to be catastrophic for many disabled people. However, the government has not published information on just how many people will be affected. We now have another week of uncertainty with disabled people not knowing what may be happening with their benefits.

“It’s crucial that these plans, and the government’s workings, can be fully scrutinised.”

Sir Stephen Timms. the Department for Work and Pensions Minister overseeing social security, conceded that the incapacity and disability benefits bill was still set to soar to £100billion but insisted the huge sum was “sustainable.”

Treasury watchdog the Office for Budget Responsibility has predicted incapacity and disability benefits are set to cost taxpayers £100.7billion by 2030, up from £64.7billion, and Sir Stephen accepted this was unlikely to change.

Interviewed in Times Radio he was asked: “The welfare bill is still climbing from £65 billion this year to £100 billion within the next five. You talk about sustainability. Do you really think that’s sustainable?” The Minister said: “Yes, it is sustainable. And we’ve taken quite bold action yesterday. You’re right, the Conservatives were saying that more should be cut. We think the balance is absolutely right.”

However Sir Stephen said there could be other savings if the Government succeeded in getting more people into work. He said: “We’ll deal with the big discouragement to work that’s been created by changes in the benefits system over the last 15 years with quite a big financial prize for being declared incapable of ever working. We’re going to fix that and instead support people on a pathway back into work.”

Conservative former Work and Pensions Secretary Sir Iain Duncan Smith said the Government had failed “to turn the benefits tide”.

He said: “We need a new vision of benefits in modern-day Britain struggling with the over medicalisation of the everyday ups and downs of life, the tsunami of so-called fit notes that sign people off work for ever, and the failure to engage employers and schools in halting the number of young people moving directly from education to their sick beds.”

Labour’s welfare cuts are set to save only £100 million despite causing enormous hardship for disabled people, a new analysis shows.

Work and Pensions Secretary Liz Kendall told MPs that her changes were expected to save more than £5 billion every year by 2030 but think tank the Disability Policy Centre said the cuts were “all pain and no gain”.

The Disability Policy Centre said the cuts were likely to save £2.8bn less than the Government claimed and would also cost taxpayers money in other ways. For example, cutting help for disabled people would increase costs for the NHS and social services by £1.2 billion while the Government would spend £400 million fighting legal challenges. In total just £100 million will be saved, the thank tank claimed.

Research Director Arun Veerappan said: “Previous attempts to reform Personal Independence Payments, in particular, have failed to produce anywhere near the savings successive governments claimed they would – and the same pattern will play out here without further changes.”

Labour backbenchers continued to criticise the cuts and left-winger Diane Abbot directly challenged the Prime Minister in the House of Commons as she told Sir Keir Starmer :”There is nothing moral about cutting benefits for what may be up to a million people.”

Conservative shadow work and pensions minister Danny Kruger asked the Government why it had failed to consult disabled people before making the announcement.

Responding in Parliament, Sir Keir said: “They had 14 years, including five with a majority, they didn’t need to consult, get on with it.

“They had a majority of 80 for the last five years. They’re now carping on with some of their ideas, 14 years and they didn’t implement a single one. They simply broke the system. They’re in no place to lecture other people.”