Social housing tenants in Northern Ireland fear they will not be able to afford food if the controversial "bedroom tax" is enforced, a senior United Nations official has claimed.
Special rapporteur on housing Raquel Rolnik also warned people will have nowhere to go because there are not enough one bedroom flats in the region's housing stock for the welfare reform.
She claimed residents nationwide could be forced to pay high rents for larger properties while having their benefits cuts, or face trying to rent in the private sector.
"It's very, very worrying," she said after holding face to face talks with those set to be affected in Belfast.
"I have been hearing issues like people would not be able to eat because much more money they receive will go on rent."
Ms Rolnik has been examining the impact of the bedroom tax - where social tenants deemed to have more bedrooms than they need have their housing benefit cut - on the human rights of low- income households.
During a two-week factfinding tour of UK cities, including Belfast, she met tenants affected by the policy as well as officials, campaigners and academics.
Unlike elsewhere in the UK, Northern Ireland has yet to introduce the Government's contentious welfare reform changes amid a political impasse at Stormont.
The Assembly has been warned by the Treasury if it does not implement the reforms by January the Northern Ireland block grant will be "adjusted".
But Ms Rolnik raised concerns over gaps in the region's social housing stock.
"In Northern Ireland, there is a shortage of one bedroom apartments in social housing stock, they do not exist," she said.
"People have nowhere to go to."
If the changes are adopted in Northern Ireland, around 32,650 (52%) working-age housing benefit claimants in the social housing sector are set to be impacted.
Opponents of the proposal insist the make-up of the social housing stock in Northern Ireland would mean many of those affected would not be able to downsize to smaller properties.
They also claim it would cost more to administer the change than the money it is designed to save.
The welfare reform bill's passage through the Assembly hit the buffers earlier this year with MLAs unable to reach consensus.
Sinn Fein and the SDLP have voiced vehement objections to the bedroom tax and have threatened to support a petition of concern mechanism that would effectively veto the proposals.
Elsewhere, Ms Rolnik criticised the treatment of members of the travelling community by planners in Northern Ireland.
"All over I see travellers facing discrimination and not having enough good quality sites and culturally adequate sites and not being part of the overall planning system," she said.
"In Scotland, Wales and England there are guidelines and through the planning system most provide sites for travellers. Not exactly social housing but places with connections to sanitation and water and where caravans can park.
"This is not the case in Northern Ireland. Travellers can apply to social housing like any other group, but there are no guidelines in the planning system for local authorities to provide these types of sites."
Ms Rolnik's final report on her factfinding mission will be presented in Geneva to the UN Human Rights Council in March.
A Department of Social Development spokeswoman said minister Nelson McCausland has on several occasions expressed concerns about the introduction of a size criteria for social housing and the challenges for Northern Ireland given the nature of our housing stock.
"The minister has been working with Executive colleagues to mitigate the impact of these reforms for Northern Ireland and would hope to reach an agreement with the other political parties which would allow the Welfare Reform Bill to progress in such a way that takes account of the particular circumstances of Northern Ireland," she added.
"The minister would also contend that his department has in place support arrangements for people who may be having difficulties as a consequence of changes to the welfare system."
These include Social Fund and Discretionary Housing payments, which people within the social housing sector are able to access to help them meet any emergency housing or daily living costs.
"The department is also working closely with the advice sector to ensure those most in need are supported."
The minister has also asked social landlords to provide a range of support measures for households that could be affected, including increasing the supply of smaller units.