Judging by the strength of his outrage, Tory party Chairman Grant Shapps is ready to draft a UN resolution sanctioning a political air strike on one of its own members.

Shapps is blazing with anger at claims by Brazilian UN official Raquel Rosnik that the government's hugely controversial so-called bedroom tax is a "shocking" breach of human rights.

In a fuming outburst he claimed the UN representative was biased, had her own anti-government agenda and was displaying astonishing brass neck in daring to criticise the UK when Brazil had a massive housing crisis of its own.

"How is it that a woman from Brazil, a country that has 50m people in inadequate housing, has come over, failed to meet with any government ministers, with any officials or even to refer to the policy by its accurate name anywhere in the report at all. She's clearly come over with an agenda," he said.

The fact the official criticised a policy that is already under fire is clearly enough to irritate ministers, but to then insist on calling it the "bedroom tax", which is Labour's derogatory characterisation of the policy aimed at reviving memories of Margaret Thatcher's damaging poll tax, has pushed Shapps to anger.

Ministers insist the policy is not a tax but the scrapping of a "spare room subsidy" for social tenants on benefits deemed to have unused bedrooms that could be used by larger families. Private tenants do not get the same allowance.

Critics claim by cutting benefits for such people they are being forced out of their homes. And they insist there are not enough alternative, fewer-bedroom properties to meet the gap.

Rosnik has claimed that the policy, which came into effect last April, was hitting "the most vulnerable, the most fragile, the people on the fringes of coping with everyday life".

And her remarks have , unsurprisingly, won support from Labour, although ministers point out the Opposition has consistently failed to say whether they would scrap the policy if returned to power.

Shapps branded her report a disgrace and has said he is writing to the UN Secretary General Ban Ki-moon asking for an apology and an explanation of how she made such a report when not invited to do so by the UK government.

Downing Street was more measured in its remarks, with the prime minister's official spokesman declaring it disagreed with the report and that: "We will continue to point out the fairness of the policy."

No need for a security council resolution after all, then.