It was "difficult" to predict what state Britain will be in once it has left the European Union, the chief executive of the world's largest staffing firm told CNBC. But, no matter what the model would be like, the U.K. government should continue allowing "brain circulation".
"What is very important is to guarantee the brain circulation," Alain Dehaze, chief executive officer at Adecco Group told CNBC
"One of the strengths of the U.K. is its ability to attract very highly talented people from all over the places, but also their ability to send English people outside. So they're very brain circulation-oriented and I do hope even with Brexit they will keep this asset they have," Dehaze added, speaking on the sidelines of the World Economic Forum in Davos, Switzerland.
On Tuesday, Prime Minister Theresa May is set to outline her plans for the U.K.'s departure from the EU. She has been under pressure from businesses and trade unions to guarantee the rights of EU citizens working in the U.K. as soon as possible. She will then travel on to Davos to speak Thursday.
A sizeable proportion of the many EU citizens working in the U.K. escaped their countries because of lack of jobs – a problem seen in many countries, including the EU's second largest market, France.
As , Dehaze suggested the future leader should reform the labor market.
France's rate is slightly above 10 percent and its youth unemployment is more than two times higher than that.
"We can only encourage the future president of France to continue reforming the labor market," Dehaze said.
"It is very important that growth is coming back in France and we are advocating for more reforms, for more simplifications and for sure more reforms on the labor market," he added.
According to Dehaze, the best way to bring down youth unemployment is by providing vocational training – a successful concept in Germany and Austria.
