Back in 2014, armed with only a laptop and phone, disabled campaigners started a hunt for the truth. As policies including the bedroom tax, the abolition of disability living allowance, and the rollout of controversial out-of-work sickness benefits hit, War on Welfare (Wow) called on the coalition government to carry out a cumulative impact assessment of the wave of disability cuts to measure the effect on disabled people. It resulted in a debate in parliament – the first time disabled people had secured a debate in the main chamber of the House of Commons – but no action.

Now, four years on, Wow has gained the backing of a cross-party coalition that wants Theresa May’s government to calculate the overall impact of the so-called welfare reforms on disabled people. Every party except the Conservatives is in favour of a Commons debate on conducting this assessment, including the DUP. In light of the pressure over Northern Irish abortion reform, their support for detailed analysis of the impact of Tory disability cuts is another awkward clash between May and the DUP’s 10 MPs propping up her administration. But more than that, it’s a sign of hope that ministers may have to finally investigate just what damage their disability cuts are causing – from the social care crisis to cuts to multiple parts of the NHS, to the disastrous rollout of universal credit; now delayed for an extra year until 2023.

Play Video 5:06 Blocked from benefits ... literally – video

Last week’s damning report by the National Audit Office (NAO) on universal credit castigated the system’s inability to protect and support “vulnerable claimants”. It follows the revelation this month that the government was forced to say it would repay thousands of severely disabled people made worse off under the UC system ahead of the high court ruling last week that it was “discriminatory” to have docked two disabled men’s benefits after transferring to UC. Following pressure from disability groups, this week ministers made another U-turn, this time to stop repeatedly testing some disabled people for personal independence payments.

The government’s austerity programme has resulted in multiple reductions in income since 2010 that have hit disabled people all at once and disproportionately. Being hit by the bedroom tax is tough – but losing your sickness benefits as well after being found “fit for work” is even harder.

If you need an insight into the damage these policies have done, just go to Wow Voices, a website set up by campaigners that features disabled people explaining the impact of cuts on them. One woman with terminal breast cancer writes of how, for the last 18 months, she’s been told she needs to be reassessed for her benefits every six months, and she’s frantic about the thought of losing her support. “I’ve cried more about this than my terminal diagnosis,” she says.

The UN’s damning report in 2016 into the UK’s “violations” of disabled people’s rights has put further pressure on the government over its treatment of disabled citizens. Meanwhile, the Equality and Human Rights Commission’s own cumulative impact assessment shows that families with a disabled adult and a disabled child will lose £5,500 a year by 2022 as a result of tax and benefit changes – contradicting the government’s claim that such analysis would be “too complex” to do.

This month, research by the Joseph Rowntree Foundation found around 650,000 people with mental and physical health problems were officially destitute in the UK last year – that means being so poor, they can’t afford deodorant, the electric, or regular meals – with social security changes found to be a key cause. It’s bad enough for ministers to take away state support from disabled people en masse, but to refuse to analyse its effects is the definition of irresponsible. The Conservatives must finally shine a light on the impact that disability cuts have had. What are they so afraid of?