New tax regulations could “severely restrict” the mobility of talent, according to Sean Drury, international mobility partner at PwC.

Guidelines seen by Accountancy Age magazine and issued to an expat forum attended by HMRC and tax firms with an interest in non-residents’ tax affairs, say: “HMRC will generally accept that working in the UK for fewer than 10 days in a year will not by itself prevent an individual claiming they have made a break with the UK because they are working full-time abroad.

“If more days than this are worked in the UK, whether an individual is working full-time abroad will depend upon their particular circumstances.”

Drury says a great many individuals who have considered themselves to be non-resident for a number of years may find their residency positioned challenged.

Drury says: “We believe 10 days is a ludicrously low figure and will severely restrict multinational corporations in conducting trade. Particular concerns would be raised where expats are working in jurisdictions with low or no tax such as the emerging and growth economies of the Middle East and South-East Asia.”