Government plans to tighten immigration rules could result in the stigmatisation of genuine refugees, create a "climate of ethnic profiling" and make it more difficult for legal migrants to find housing and integrate in the UK, the United Nations refugee agency has warned.
The Immigration Bill, currently going through Parliament, will make landlords liable to fines if they rent homes to illegal immigrants and bar banks from opening accounts for migrants without the right to stay in the UK.
Temporary immigrants will be required to contribute towards the cost of services such as the NHS and reduce rights to appeal against the rejection of asylum claims.
In a letter to MPs, obtained by The Guardian, the UN High Commissioner for Refugees Antonio Guterres warned that legal asylum-seekers and refugees may be caught up in the changes and suffer as a result.
Landlords will face bureaucratic burdens from the new requirement to check the immigration status of tenants and may not be able correctly to interpret documents provided to them, leading to the denial of housing to people in need, he warned.
Mr Guterres wrote: " The provisions of the bill appear likely to result in asylum seekers, refugees and beneficiaries of subsidiary protection being stigmatised in the public mind and in their being denied access to housing or bank accounts.
"The UN High Commissioner for Refugees is concerned that if introduced, such measures could contribute towards a climate of misunderstanding and ethnic profiling that could undermine the longer-term prospects for integration of such persons and prove detrimental to social cohesion.
"Additionally, the UN Commissioner for Refugees is concerned that the types of documentation carried by asylum-seekers, refugees, beneficiaries of subsidiary protection and stateless people can be varied and complex and landlords and other service providers are likely to misinterpret the legality of their status.
"It will impose an additional administrative burden on them. These challenges may have unintended consequences, such as the denial of housing and other services to asylum seekers, refugees and beneficiaries of subsidiary protection that result in their marginalisation and inhibit their integration in the United Kingdom."
Immigration minister Mark Harper said in October that the Bill would "stop migrants abusing public services to which they are not entitled, reduce the pull factors which draw illegal immigrants to the UK and make it easier to remove people who should not be here".