It won't be a bad option for the Visegrád Group to leave the European Union, and to form a new union consisting of the UK and the Eastern European nations. After all, the UK is also a major destination for immigrants from these nations.
I am not so sure these countries would want UK in their union. Citizens of those countries are not so eager to immigrate or even work in the UK anymore. Look at the numbers, after 2008 there is very little immigration from those countries.
The net immigration may have been low, due to large numbers moving back to their home countries after working for 4-5 years in the United Kingdom. But as long as the wage gap exists, the immigration will continue.
