Realized why the Brexit deal is so big in the EU right now politically. If the UK leaves post election, their seats have to get redistributed. From the Guardian:

"The current European Parliament is comprised of 751 seats, of which 73 are for UK MEPs. This will remain the composition of the Parliament for as long as the UK remains a member of the EU.

As soon as the UK departs, it will have to be reconstituted, becoming a 705-seat Parliament, with 27 UK seats being re-allocated to other EU nations in order to re-balance the Parliament.

Spain and France get five more seats, Italy and the Netherlands get three, Ireland two and a host of other states - Germany, Denmark, Estonia, Croatia, Sweden, Romania, Slovakia, Austria, Poland - receiving one more seat."

Sauce: https://www.telegraph.co.uk/politics/2019/05/23/european-elections-2019-results/

Spain, France, Italy, and Netherlands are rapidly going full MAGA, this redistribution would shift the balance of power. Potentially, a majority of the MEPs from those countries would be white hats, and a lot of the British MEPs leaving wouldn't be.

Brexit could completely reshape the EU, far more than just losing one country.