As an example, they brought out that in Poland a foreigner cannot be a candidate in any elections, nor can he vote in parliamentary elections. Only EU citizens, resident for more than three years in Poland, can vote in administrative elections.
EU citizens can vote in municipal and European elections from the minute they obtain the EU residence certificate, which takes about a month at the most to get. They need to go to the Urzad Miasta each time to get a paper which confirms their vote - but that's a five second job.
The rules are harmonised throughout the EU in this respect - those with valid residency can vote in these elections. Incidentally, they can also be candidates if they chose to be. It would be rather insane if a European Union citizen couldn't stand for European election!
As it stands, I can't think of anything in Poland that EU citizens cannot do that Poles can do, except voting. Heck, there's even an Nigerian posel!