THE United Nations launched a probe into the British government’s vindictive attacks on welfare yesterday, including the “medieval” two-child tax credit limit.

Two of the measures announced in last year’s Budget will be investigated after SNP MP Alison Thewliss wrote to UN secretary-general Ban Ki Moon about potential human rights breaches.

Ms Thewliss described the limitation of tax credits to families with two children or fewer, and a subclause that would force women to prove they had been raped to claim their benefits, as “medieval.”

The Glasgow Central MP welcomed the UN intervention to “shine a very bright light onto this cruel and thoughtless government, which appears hell-bent on making life as difficult as possible for ordinary people.”

She said: “It is clear that, over the last 10 months, the Tories had hoped this campaign would be quietly dropped but the fact it has caught the attention of the UN suggests this policy is now totally untenable.

“This government simply cannot be allowed to get away with a policy that is tantamount to social engineering.”

The SNP believes the “unworkable” and “immoral” measures would breach at least five of the 54 articles in the UN Convention of the Rights of the Child.

Article four of the convention — signed by Britain in 1990 — states that governments have the responsibility for children’s “economic, social and cultural rights” and must “undertake such measures to the maximum extent of their available resources and, where needed, within the framework of international co-operation.”

New rules limiting child tax credits to two children, unless the third child is a result of rape, have yet to be implemented.

A Department for Work and Pensions spokesman said: “We know this is a sensitive issue and have been clear that we will develop appropriate exemptions and protections.

“We want to make sure this support is compassionate and effective, which is why we are engaging with MPs and working with a range of stakeholders, including religious groups, to ensure this exemption is delivered in the best way possible.”

SNP deputy leader Stewart Hosie announced he would quit in the autumn following intense scrutiny from the press over his alleged affair with Westminster journalist Serena Cowdy.