Iain Duncan Smith, the Secretary of State for Work and Pensions
Iain Duncan Smith's Department for Work & Pensions has come under fire from UN Getty

The UN is set to challenge the UK government over Department for Work & Pensions (DWP) boss Iain Duncan Smith's controversial welfare reforms to gauge whether they have caused "grave or systematic" violations to the human rights of disabled individuals. Costa Rican human rights lawyer Catalina Devandas Aguilar will visit the UK in the next few months to investigate claims that rights are being violated putting the government on the ropes over new laws including the bedroom tax.

A UN special investigation on housing has already raised concerns over the welfare reforms and called upon the UK government to scrap the bedroom tax, which financially penalises disabled people for having a "spare" room within their house. Commentators and disabled charities have pointed out that many disabled people need the extra room to store equipment that is essential to their disability.

Speaking to the Sunday Herald Inclusion Scotland, a consortium of disability charities in Scotland, said that it had already been contacted by the UN Committee on the Rights of Persons. Director of policy Bill Scott told the paper: "The UN have notified us they will be visiting Britain to investigate... sometime in the next few months."

The DWP has fought to keep the numbers of deaths linked to welfare reforms out of the public domain. However, last week it was forced to reveal that 2,380 people had died as a result of the changes in the way the government measures benefits. The number refers to the number of people who had died within six weeks of being declared "fit to work" by the government between 2011 and 2014.

In July this year the much-challenged Welfare Reform and Work Bill passed through the House of Commons on its second reading by 308 votes to 124. Despite 48 out of 216 Labour MPs going against the whip that had been encouraged by the acting leader of the party Harriet Harman and voting against the bill, the majority abstained, letting the bill pass with a large majority. Abstainers included current contenders for the Labour leadership Andy Burnham. Yvette Cooper and Liz Kendall.

The Scottish National Party (SNP) has criticised the DWP over recent instructions issued to its staff on how to handle suicidal benefits claimants.

What is the bedroom tax?

If you are a working-age council or housing association tenant your local council may limit your housing benefit claim if it decides you have 'spare' bedrooms.

This housing benefit reduction is called the under-occupancy charge but is more commonly known as the bedroom tax.

The number of bedrooms you can claim for is based on the number of people living in your home and the tenant is expected to pay any outstanding rent themselves.

The amount of rent you can claim housing benefit for is reduced by 14% if you have one spare bedroom and 25% if you have two or more spare bedrooms.