In conjoined appeals in Wilson v. St. Helens Borough Council [1998] 3 W.L.R. 1070, the House of Lords considered two important questions concerning the Transfer of Undertakings (Protection of Employment) Regulations 1981, S.I. 1981/1794, which enact the Acquired Rights Directive (77/187/EEC): first, whether a purported dismissal of an employee, the reason or principal reason for which is the transfer of an undertaking, is effective or is a nullity, and secondly, the extent to which employees are free, expressly or by conduct, to accept variations by the transferee in their terms of employment.