As a side note, in my opinion, this is a result of our current governmental situation, which is unprecedented: the center-right party won a relative majority, but the center-left party got the Communist Party and the Left-Bloc (an anti-capitalist left-wing party but without just a single guiding ideology) to support it in Parliament and allow it to form government.
This has had many effects, but this bill in particular was introduced by the Left-Bloc, and then voted favorably by all the left (and by the single representative of the party "People, Animals and Nature", which doesn't consider itself left- or right-wing).