The forthcoming ETUI study on EWCs’ access to justice provides an insightful overview of the level of sanctions across the EU. Suffice to say that sanctions for breaching EWC rights are sometimes included in the transposition acts implementing the directive, but on many occasions also scattered across external acts, which does not help legal transparency and ease of reference (especially for employee representatives from abroad). Moreover, the levels of sanctions differ significantly across the EU, leading to excessive variation in the protection of those rights.
More insight can be found in chapter 7 of the Benchmarking report, available as free pdf download on the ETUI website. See also the ETUI's recent policy brief on this topic.