Basically the law change is this:
Now, if you are Polish truck driver employed in Poland, you are subject to Polish tax and labor codes, including things like tax rate, minimum wage, etc. What France wants (and what was passed, but is not in effect yet) is that if said truck driver crosses the border of another country (say, France) he should be subject to that country tax and labor code. Which is riddiculous, because the driver does not change his tax residence, he just enters France for a few days it takes to make a delivery, and then comes back to Poland.