Well a law was passed prior to the election last November. It states that on all Catholic holidays every business must close. They even included gas stations, but someone figured out that was completely ridiculous since so many people travel on those days. They found a loophole that allowed some places to be open if only the owner worked, none of the employed workers are allowed to work on those days. I wouldn't be surprised if their next move is to make it a law that all businesses must be closed on Sundays. Many churches this Saturday where pushing this sin as being very important.

For those that can't read polish, "Shopping on Sunday"
The mandatory religion course, which really only covers Catholicism is also in all schools. You can opt of out it and they are supposed to have an ethics class as a substitute, but the majority of schools don't offer that, so the student will just sit in an empty classroom for that time period.
The church has a lot of influence in shaping policy.