The decision to leave the European Union could be damaging to Britain’s access to top international talent, with UK’s key ‘powerhouse’ sectors likely to be hit the hardest.

The restricted movement of EU workers that Brexit presents could cut international talent in the UK by 40%, according to new research by LinkedIn.

LinkedIn’s professional migration data reveals that the EU-27 states have accounted for 40% of professional migration to the UK since January 2013, making these states collectively the biggest foreign supplier of professional workers to British businesses in the last three years, far ahead of North America (17%) and Asia (14%).

The UK’s Professional Services sector is the most reliant on professional migration from the EU and therefore at the greatest risk of a ‘Brexit talent block’, followed by Technology, and Financial Services and Insurance respectively.

The data even finds that EU workers are 50% more likely to be working in the UK’s Professional Services industry compared to the general UK professional population. This is 30% more for Technology and 20% for Financial Services and Insurance.

Josh Graff, UK country manager at LinkedIn, said: ‘‘There has already been a lot of debate about the impact of Brexit on blue-collar workers, but British businesses also face a very real white-collar skills gap that they need to start thinking about.

“Our findings are clear: UK companies need to prepare themselves for a more difficult talent market, and may want to start looking at how they can develop more talent at home, or cast the net further. The USA and Australia already account for over a fifth of professional migration to the UK, so they are a good place to start.’’

The data also reveals that almost two thirds (61%) of professional migrants from the EU-27 have a masters or doctorate degree - far higher than the general UK professional population (34%), signalling that a future restriction on EU migration could deny UK businesses some of the world’s most-educated workers.

Mr Graff added: ‘‘If businesses are depending on talent from overseas to be competitive, it is time for them to let the government know, so that they negotiate a settlement that can support Britain's success.

“In turn, we’re calling on Government to ensure that maintaining access to talent is one of the key priorities when negotiations begin.”