  Debates on an EU-leaving referendum arose in several member states after
Brexit. We want to highlight how the exit of an additional country affects the
power distribution in the Council of the European Union. We inspect the power
indices of the member states both with and without the country which might
leave the union. Our results show a pattern connected to a change in the
threshold of the number of member states required for a decision. An exit that
modifies this threshold benefits the countries with high population, while an
exit that does not cause such a change benefits the small member states.
According to our calculations, the threat of Brexit would have worked
differently before the entry of Croatia.
