WHEN Theresa May signed off on the measure to exempt victims of rape from the Government's cap on the number of children eligible for benefits, did she realise that she was alienating one of the most organised and vociferous group in Scottish politics, the women’s movement? As a woman herself, you'd have thought she might. The “rape clause”, as it is now universally known, has appalled women – and men – of all political backgrounds.

Press coverage of the eight-page form that raped mothers must complete has been hugely damaging to the Scottish Conservative campaign in the local elections in May. No politician can risk being on the wrong side of rape – however indirectly. Indeed, it is beginning to look as if the clause has halted the Scottish Tory revival in Scotland, at least for the time being, as the Scottish Tory leader, Ruth Davidson, continues to tie herself in moral contradictions on the issue.

On any level, the “vile” rape clause is an abomination. The idea of compelling victims of rape to revisit the experience and compile evidence in order to claim benefits is simply inhumane, not least to the children so identified. It is also unworkable. It will require bureaucrats to adjudicate on sensitive issues like marital rape and coercive control – issues they aren't trained to deal with. Judges find it difficult enough to give guidance on these issues, so the idea of social security jobsworths assessing rape evidence is abhorrent.

The measure looks like a reversion to the ruthless approach to social policy which earned the Conservatives the soubriquet “the nasty party”. But Ruth Davidson was supposed to represent a fresh break with crusty Tory tradition. She is in a gay relationship and has been assumed to be in favour of women's rights. That reputation all but evaporated over the past week as she initially attempted to defend the rape clause, and then tried to blame the Scottish Government for not reversing it – even though it is a UK policy on which the Scottish Parliament has no legislative authority. When the rape clause row first broke, on the eve of its implementation earlier this month, Davidson tried to avoid all mention of it. Then last week her spokesman issued a belated statement on her behalf endorsing the two-child cap, claiming that Labour in Westminster had not opposed it, and promising to give women the help of “experienced third-party professionals” when claiming an exemption on grounds of rape. This only inflamed the row.

The Scottish Labour Party leader, Kezia Dugdale, fulminated against the “disgusting” and “barbaric” policy. In an extraordinary and rare show of cross-party unity during an election campaign, she even congratulated the SNP MP, Alison Thewliss, for her “tireless campaigning” on this “horrifically cruel and uncaring policy”. As the Liberal Democrat leader, Tim Farron, weighed in against the Tories on his visit to Scotland last week, the Tories realised that the issue was now a political firestorm. Something had to be done. Unfortunately, what they did poured petrol on the flames.

In her first substantive interview on the issue, Ruth Davidson tried to turn the tables on the Scottish Government, claiming they could reverse the policy if they wished. “At Holyrood we have the power to create new benefits,” she said. “If the Scottish Government believes this to be of such importance, it can act.” This is of course a ridiculous proposal. The Scottish Government has some new welfare powers, but it emphatically does not have the power to reverse the Universal Credit policy of which the two-child cap is a part. It could perhaps try to compensate the victims by raising money though Scotland’s new income tax policies, to give additional money to families with more than two children. But that does not reverse the policy, which is a Westminster one.

Her subsequent accusation of “grotesque hypocrisy” against Nicola Sturgeon for not favouring this approach rebounded. It drew attention to the fact that Davidson is a supporter of the policy for which she was now calling on the Scottish Government to reverse. Her discomfort at this contradiction was palpable. I don't think anyone believes that she is privately supports the rape clause, but she clearly had no choice but to defend it.

Her predicament rather vindicated the controversial claim made by the SNP's Edinburgh group leader, Frank Ross, who said that the Scottish Tories weren't really “Scottish”, because they had to accept the policy agenda of the UK Conservative and Unionist Party. Ruth Davidson has criticised her own party's policies before – and of course she voted Remain in the EU referendum – but during an election it would be political suicide to actively challenge a central plank of the UK Government's welfare reforms, especially when the Tory party's main message in the election is to stick with the Union and therefore Westminster policy.

Rape is only one dimension of the two-child cap. It is anyway extraordinary for the UK Government to be dictating how many children families should have. In the past this would have been condemned by many as victimising the innocent: the third child does not ask to be born, and yet is being penalised for coming up wrongly in the numbers game. It is perhaps a measure of how intolerant we have become as a society that this only became politically “weaponised” because of the rape clause. Such has been the demonisation of benefit claimants, that these measures no longer generate much public opposition.

Yet, welfare recipients in and out of work are getting a very rough deal as the UK Government works through George Osborne’s £12bn programme of cuts to the social security budget. The four-year working-age benefit freeze was not eased in the last budget as many seem to believe. This means Jobseekers Allowance, Employment and Support Allowance, Income Support, Housing Benefit, Universal Credit, Child Tax Credits, Working Tax Credits and Child Benefit are all being cut in real terms. As inflation rockets in food and fuel prices, this could cause very real hardship.

Disabled people are facing the loss of benefits if they can't prove their inability to perform “work-related activity”, whatever that is. This may not generate such lurid headlines as the rape clause, but it represents humiliation for thousands of people with disabilities. Young people are also being hit as they lose the right to housing benefits. Universal Credit itself will lead to families losing over £1000 each a year by 2020, according to the Resolution Foundation.

The UK Conservatives should rightly be taken to task for these policies, which apply in Scotland as elsewhere in the UK. However, there is a longer-term problem here for the Scottish Government. It is rightly outraged at the suggestion it should be held responsible for the rape clause. But over the years, demand will build for it to start using its tax-raising powers to mitigate many Tory benefit reforms, as it has already with the bedroom tax. Politics is the language of priorities and eventually Nicola Sturgeon is going to have to decide whether she gives priority to compensating rape victims with children. But in the meantime, it is Ruth Davidson who is rightly in the moral firing line, and likely to stay there.

It's most unusual for this kind of issue to dominate an election campaign, especially a local government one. Councils have even less power over welfare policy than Holyrood. But there seems little prospect of the rape clause row dying down any time soon. The Scottish Conservatives had hoped the May election campaign would turn into a kind of referendum on indyref2. The Prime Minister, Theresa May, even called on Scottish voters to “send a clear message” that they don’t want another independence referendum. Well, they're sending a message back that they don’t believe the Conservatives have changed their spots. The rape clause confirms that, for many Scottish voters, Tory is still a four-letter word.