Could Universal Credit become Prime Minister Theresa May’s Poll Tax – the mean and miserly benefit whose grim roll-out prompts an unexpected Conservative revolt, weaponising Arlene Foster’s threat to the Budget and thereby triggering a general election?

On the face of it, that does seem unlikely.

The continuing and deepening nightmare of Brexit means the imminent meltdown facing benefit claimants is nowhere near the top of the political or media agenda. Even though homelessness, rent arrears and evictions have been soaring everywhere Universal Credit has arrived. Even though savings from the penny-pinching rules have simply increased pressure on other public services. Even though the stories of individual hardship caused by the harsh month without income endured by new claimants would make a stone weep. Even though, as Labour Party chairman Ian Lavery predicted this weekend: “The roll-out will lead to increased suicides and the unnecessary deaths of people forced into desperation.”

Ruth Davidson faces a test on Unviersal Credit. Picture: Jane Barlow/PA Wire

It’s all been said before – to no avail. But finally, the low political profile of Universal Credit is changing. Last week, former Tory prime minister John Major said the unfairness of the “six-in-one” benefit will damage the Tories as much as the Poll Tax. Former Labour prime minister Gordon Brown warned the ongoing UC roll-out would cause chaos and Poll Tax-style riots. And Mrs May was forced to promise that claimants being migrated to UC will not see any reduction in benefits – “they will be protected”. It’s become clear this weekend, though, that the Prime Minister’s assurance is almost worthless.

For one thing, the “guarantee” applies only to existing claimants being switched to Universal Credit. According to Josephine Tucker of the Child Poverty Action Group, they constitute just two million of an expected seven million claimants, the bulk of whom will fall into the system not through planned “migration” but because their circumstances change. For these luckless folk, the vast majority of claimants, there is no guarantee – nothing to stop them losing between £200 and £2,000 a year.

Secondly, despite “being migrated” by the Department of Work and Pensions, existing claimants have to make entirely new claims for Universal Credit with as little as a month’s notice, presumably in the hope that the complex internet application process will force delays and small mistakes causing hundreds of thousands of existing claimants to have their claims rejected – they will fall outside the scope of the income guarantee as well.

Thirdly, and most shockingly, the folk most likely to lose money are disabled children. Weeks after she declared austerity to be over, Mrs May will pass a Budget removing £30 a week from 100,000 disabled children – that represents a 50 per cent cut on their benefits on the previous tax credit system. Weeks after her appointment of a “suicide prevention tsar”, Mrs May’s budget will remove £30-£60 a week from a quarter of a million severely disabled adults living difficult, often lonely lives without a spouse or carer. According to Ms Tucker, protection has been promised for this latter group but it’s too little and time limited.

Finally, contrary to Esther McVey’s warm words about winners in the new system, there will actually be more losers. According to David Finch of the Resolution Foundation 2.2 million people will gain an extra £40 a week – but 3.2 million will lose £48 a week.

The casual cruelty is appalling. That’s why 27 Tory backbenchers, led by Iain Duncan Smith, wrote to the Chancellor this weekend demanding an extra £2 billion for Universal Credit in the Budget. It’s rumoured Boris Johnson may join the UC rebels along with Brexiteers from the European Research Group. It may be a motley crew, but it’s a powerful lobby, motivated by the knowledge that the Prime Minister’s promise to prevent income loss among folk forced onto Universal Credit is utterly hollow. Is this enough to prompt change by Budget Day on 29 October?

With a possible general election on the horizon – maybe it is. And in the Scottish political sphere, there could be even greater repercussions for Ms Davidson. Her weekend announcement about resigning as Scottish Conservative leader if Northern Ireland gets an EU deal denied to Scotland suggests she and Mr Mundell either think such an eventuality is unlikely or hope their apparently selfless gesture will be applauded by Scottish voters and allow the Scottish party to distance itself from Mrs May and Tory London HQ whilst the fires of Brexit are still burning.

After all, Ms Davidson’s recent decision to choose a political career in Scotland, not Westminster, means she can put some clear blue water between herself and the chaotic, immigrant-phobic, back-stabbing and EU-blaming British party to create a political base in Scotland with appeal beyond mere support for the Union. She therefore needs the UK government’s nasty, vindictive welfare “reforms” like a hole in the head.

Fairness is a big part of the Scottish political psyche and spans all political divides. The SNP’s creation of a Scottish welfare system, with hundreds of millions spent mitigating and humanising the harsh Westminster benefits regime, is hard for Ms Davidson to knock or for many Scots voters to condemn. Meanwhile, her credentials as a working-class Tory are hugely damaged by helping to inflict the discredited Universal Credit on her supposed class peers.

Maybe Tories in the Home Counties can dismiss critics with “let them eat cake” style high-handedness, but that doesn’t work in Scotland. So I wouldn’t be surprised if the enterprising Ms Davidson is trying to use the Brexit crisis to cut herself loose from London High Command altogether by establishing a standalone Scottish Conservative Party.

If the Scottish Tory leader does want to engineer a split from her erstwhile southern colleagues, resignation on a point of Brexit-related principle may tear the Scottish party asunder, but will doubtless see her return to the leadership having demonstrated a willingness to sacrifice her career for the greater good of Scotland.

Far-fetched? Too cynical?

Maybe. But a big test for Ms Davidson occurs in two weeks’ time.

Her Scottish Tory MPs can prove they are not members of the UK nasty party by demanding work allowances are restored, the freeze on benefits is ended and the roll-out of Universal Credit halted pending a complete review. Or is protecting the most vulnerable folk in Britain not actually worth the candle?

Lesley Riddoch: Will Universal Credit trip up Theresa May?