Changing bonus rules could be seen as collective redundancy

Employers planning measures that may lead to numerous employee terminations within a short timeframe must always anticipate the most far-reaching consequences.  When giving notices to change employment terms and conditions, employers should anticipate that not all employees will accept them and consider whether the changes might inadvertently constitute collective redundancies. – Mariusz Maksis comments for Rzeczpospolita.

Full article in Polish avialible here.