Article 21

1. An employer domiciled in a Member State may be sued:
(a) in the courts of the Member State in which he is domiciled; or
(b) in another Member State:
(i) in the courts for the place where or from where the employee habitually carries out his work or in the courts for the last place where he did so; or
(ii) if the employee does not or did not habitually carry out his work in any one country, in the courts for the place where the business which engaged the employee is or was situated.

2. An employer not domiciled in a Member State may be sued in a court of a Member State in accordance with point (b) of paragraph 1.