Citizens Advice Northern Ireland confirmed that it had seen an 80 per cent year-on-year rise in immigration queries from 873 in 2015/16 to 1,580 in 2016/17.

There was a 612 per cent increase in questions on nationality and citizenship from 43 to 306. There were no queries about visitor visas before July 2016, but there were 50 over the next year.

The highest number of enquiries (976) concerned families, dependants and partners.

A spokesperson for Citizens Advice warned that it was “concerned with the lack of provision of free specialist immigration advice in Northern Ireland” and called on the government to “increase funding for such advice”.

The charity was unable to provide figures for 2017/18 due to redundancies caused by a funding crisis, but said it had received 943 immigration enquiries between April-December 2017.

Professor Colin Harvey, a human rights expert in QUB School of Law, told The Detail: “This is a worrying time for migrants, refugees and asylum-seekers. We have witnessed successive governments implementing ever more repressive measures. These have tended to focus on deterrence and deflection. Brexit has only added to an already troubling picture.

“This is a complex and difficult area of law, the level of complexity has itself been the subject of extensive and justified criticism. With that in mind, it is essential that people are able to access reliable and timely legal advice. This remains a real problem in Northern Ireland and one that is too often neglected.”