Article 12 2.

The second sentence of paragraph 1 shall not prevent national rules relating to time limits for bringing actions under national law from being relied on against workers or those claiming under them who initiated legal proceedings or raised an equivalent claim under national law before 17 May 1990, provided that they are not less favourable for that type of action than for similar actions of a domestic nature and that they do not render the exercise of rights conferred by Community law impossible in practice.