More than a million foreign workers are preparing to ditch Britain, adding to fears that the country is facing a Brexit brain drain, new research shows.
The survey by accountancy giant Deloitte shows that 36% of non-British workers currently in the country say they are thinking about leaving by 2022, with 26% planning to move even sooner, by 2020.
This figure represents 1.2 million jobs out of 3.4 million migrant workers in Britain, underscoring the severe jobs crisis facing the country as it begins the process of extracting itself from the EU.
Highly-skilled workers from EU countries are the most likely to consider leaving, with 47% thinking about upping sticks in the next five years.
To change their minds and stay, 32% of skilled foreign workers said they would need to hear more positive statements from the Government that they remain welcome.
Lower cost of living and more initiatives to improve work-life balance would also help, respondents said.
The findings are likely to increase political pressure to ensure access to talent is maintained following Brexit.
David Sproul, senior partner and chief executive of Deloitte North West Europe, said: "Overseas workers, especially those from the EU, tell us they are more likely to leave the UK than before.
"That points to a short-to-medium term skills deficit that can be met in part by upskilling our domestic workforce but which would also benefit from an immigration system that is attuned to the needs of the economy."
Theresa May has laid out her plans to grant EU nationals in the UK "settled status" and the right to stay in the country after Brexit.
But the offer is contingent on Britons in Europe receiving an equivalent deal, which means Europeans in the UK are still living under a cloud of uncertainty.
"The uncertainty started ticking a year ago, at the time of the EU referendum result," said Angus Knowles-Cutler, vice chairman and London senior partner at Deloitte.
"At times of uncertainty, skilled workers are quickest to get their CVs out," he added. "You can't necessarily expect all the best and brightest to wait around for another few years of uncertainty."
Faced with the potential loss of so many migrant workers, the survey suggests employers will struggle to fill the skills gap.
Almost half (48%) of migrant workers already in the UK see the country as being less attractive as a result of Brexit, the study showed, while highly-skilled workers reported the largest drops in the attractiveness of the UK.
However, increased use of automation could be one way of avoiding a longer-term skills gap and presents a "golden opportunity", according to Deloitte.
"Automation is beginning to transform the world of work," said Mr Knowles-Cutler.
"Brexit does not change the fundamental factors shaping this but has altered calculations on how to drive change for best advantage.
"If immigration and upskilling can help fill higher skill roles, automation can help to reduce reliance in lower skill positions.
"There is a golden opportunity for UK workers and UK productivity if we get it right," he added.
Employers can also take comfort in the fact that the UK overall retains its appeal as a place to live and work.
Despite Brexit uncertainty, 89% of non-British workers say they find the UK either quite attractive or highly attractive as a work destination.
For respondents based outside the UK, the country ranked as the most desirable place to work ahead of the US, Australia and Canada.
Mr Sproul said: "Despite political and economic uncertainties, more people are attracted to live and work in the UK than anywhere else in the world."
Deloitte surveyed 2,242 EU and non-EU workers, half living in the UK and half living outside.