Nullifying a collective agreement is strictly regulated by the provisions of article L. 2262-14 of the Labour Code and must take place within two months. If the judge recognises the nullity of a collective agreement, it is retroactive and enforceable against third parties.

What if such an action has not been initiated within the time limit, even though a collective agreement is tainted by illegality? Is any action futile and who can initiate it?

In three separate rulings rendered on 2 March 2022,(1) the Plenary Chamber of the Court of Cassation recognised the right of social and economic committees and trade unions that are not signatories of a collective agreement to challenge the illegality of a clause in a collective agreement when it is invoked to oppose the exercise of their legally provided rights.

If the illegality of the agreement is recognised by way of exception and without any time limit, the punishment is the unenforceability (not the nullity) of the agreement, with respect to the petitioners only.

For further information on this topic please contact Alexandra Tuil at Hogan Lovells by telephone (+33 1 53 67 47 47) or email ([email protected]​ The Hogan Lovells website can be accessed at


(1) They are: