Many companies have already drawn contingency plans in case Britain makes an uncontrolled departure from the EU, according to the Confederation of British Industry (CBI), which also attended the meeting with May.
France and Germany have been the main forces behind European integration and the relationship between their respective leaders has been intrinsic to the development of the European Union.
In the peaceful vineyards of France's Bordeaux region, a potential EU crackdown on a popular weedkiller over cancer fears is adding to winemakers' worries.
In addition to EU member states, countries of Norway, Switzerland and Lichtenstein have committed to relocating people. Norway has accepted 1,508 relocated people, Switzerland 1,122 and Lichtenstein 10.
Last year, Italy replaced Greece as the main destination for Europe-bound sea migrants. About 98,000 migrants have landed on its shores since the beginning of the year.