certain members that you are exhibiting strange behaviour  to say the least treating the assort dumping ground their problems without too much about the common interest
Certain existing Members of the EU are exhibiting strange behaviour, to say the least, treating the EU as a sort of dumping ground for their problems without worrying too much about the common interest.
Certain Members the EU are exhibiting strange behaviour, to say the least, treating the a sort dumping ground their problems without too much about the common interest.