Where an employer is carrying out a redundancy exercise involving fewer than 20 employees but a need to make further redundancies subsequently arises, taking the total number of employees to 20 or more, is it obliged to consult collectively?
Where an employer is proposing to dismiss 20 or more employees as redundant at one establishment in any 90-day period, it must consult collectively with representatives of the employees concerned. (In Usdaw and another v WW Realisation 1 Ltd (in liquidation) and others  IRLR 577 ECJ, the European Court of Justice confirmed that "establishment" means the entity to which the employees are assigned to carry out their duties, not the employer's organisation as a whole.)
If the employer has already started a redundancy exercise to which the duty to consult collectively did not apply as fewer than 20 employees were involved, it should add the two groups of employees together. It will be required to consult collectively if the total number of employees to be dismissed is at least 20 and if it is proposed that all the redundancies will be made within a 90-day period.