A member of the British government has demanded an apology from the UN after an investigation by the world body criticised welfare policy.

Raquel Rolnik, the UN rapporteur on housing, says the UK's "bedroom tax" should be abolished as it punishes the most vulnerable in society.

In an exclusive interview with Al Jazeera, Rolnik says she found parts of the country's benefits system shocking.

Al Jazeera's Laurence Lee reports from London.

Source: Al Jazeera