Nevertheless, even if the United Kingdom were free to impose restrictions, it is questionable how effective these would be in the near term. There could be a “rush for the border” ahead of the restrictions, resulting in a surge in migration in the short term. European Union migrants already in Britain would almost certainly be given leave to stay, just as British citizens living in Europe could remain there. Furthermore, if European Union migrants already in the United Kingdom knew that it would be hard to get back in if they left, they might stay longer than they otherwise would have. Emigration out of Britain could fall alongside a rise in immigration, perhaps leaving net migration little changed or even higher in the short term.