When Sweden voted to join the EU there was a lot of talk about the subsidiary principle[0], but it seems almost completely forgotten now.
I guess one could argue that it affects the internal labour market in some way, but so could pretty much any issue. I would love to see more members of the EU parliament vote against proposals like this, but I guess it's hard to be on record as saying no to something you might be in favour of - if raised on another level.
[0] "Specifically, it is the principle whereby the EU does not take action (except in the areas that fall within its exclusive competence), unless it is more effective than action taken at national, regional or local level." (https://eur-lex.europa.eu/summary/glossary/subsidiarity.html)