More than a quarter of British employers say that staff members from other European Union countries have considered leaving jobs at their firms or leaving the country itself in 2017 after last year’s Brexit vote, an industry group said on Monday.

43 percent of employers in education and 49 percent in healthcare sector employers also state that staff have expressed a desire to leave the UK or their career. This comes from a recent survey of more than 1,000 companies that was conducted by the Chartered Institute of Personnel and Development (CIPD).

The CIPD said Britain’s labour market continues to be in a strong position, but British citizens’ decision to leave the European Union is likely to force companies to reform their training strategies, in order to adapt to employing future non-UK EU citizens s in future.

Prime Minister Theresa May has promised greater control over immigration levels after Britain divorces the European Union, which is likely to occur in 2019, even if this results in the UK losing its open, unrestricted access to the EU’s single market.

The CIPD said recent official data showed employers who rely heavily on EU migrant workers were struggling to fill some vacancies: firms in retail and wholesale, manufacturing, health and accommodation and food services accounted for 45 percent of vacancies in late 2016.

Gerwyn Davies, the CIPD’s labour market adviser, said that the official data also displayed how the amount of EU nationals working in Britain increased at a slower rate in the three months leading up to September compared to before the referendum.

“This is creating significant recruitment challenges in sectors that have historically relied on non-UK labour to fill roles and who are particularly vulnerable to the prospect of future changes to EU immigration policy,” he said.

Last year the British farm sector began to show signs of a shortage in migrant workers shortly after June’s referendum. This coincided with the decreasing value of pound sterling, resulting in making the UK a less attractive destination for work.