A proposed law on working hours this week will pit the parliament in Strasbourg against divided national governments.
The Euro-parliament wants to offer further defence of the European social model in the directive.
The text being put to a vote this Wednesday aims to limit more strictly situations in which employees work more than 48 hours per week — the maximum allowed by the European Union.
The weekly averages EU member states apply now vary broadly — highest in Britain (48 hours), lowest in France (35 hours).
Some of them want opt-outs curtailed but the UK is leading a group calling for fewer constraints.
Parliament’s report in the matter recommends phasing out exceptions altogether.
Labour unions says what’s at stake includes safety, room for family life, and avoiding social dumping.
Another part of the legislation in urgent need of a consensus among the 25 is what counts as paid time for workers required to be on call, such as doctors on duty in hospitals.