"Article 1(a) 'Collective redundancies' means dismissals effected by an employer for one or more reasons not related to the individual workers concerned where ... the number of redundancies is ... (2) over a period of 90 days at least 20, whatever the number of workers normally employed in the establishments in question."
"Where an employer is proposing to dismiss as redundant 20 or more employees at one establishment within a period of 90 days or less, the employer shall consult about the dismissals all the persons who are appropriate representatives of any of the employees who may be affected by the proposed dismissals or may be affected by measures taken in connection with those dismissals."