"A full-time worker is a comparable full-time worker in relation to a part-time worker if, at the time when the treatment that is alleged to be less favourable to the part-time worker takes place - (a) both workers are – (i) employed by the same employer under the same type of contract, and (ii) engaged in the same or broadly similar work having regard, where relevant, to whether they have a similar level of qualification, skills and experience; and (b) the full-time worker works or is based at the same establishment as the part-time worker or, where there is no full-time worker working or based at that establishment who satisfies the requirements of sub-paragraph (a), works or is based at a different establishment and satisfies those requirements."
"men shall be treated as in the same employment with a woman if they are men employed by her employer or any associated employer in the same establishment or at establishments in Great Britain…"
"Notwithstanding reg. 2(4), reg. 5 [right not to be less favourably treated] shall apply to a worker to whom this reg. applies as if he were a part-time worker and as if there were a comparable full-time worker employed under the terms that applied to him immediately before the variation or termination."
"The term' comparable full-time worker' means a full-time worker in the same establishment having the same type of employment contract or relationship, who is engaged in the same or a similar work/occupation, due regard being given to other considerations which may include seniority and qualification/skills. Where there is no comparable full-time worker in the same establishment, the comparison shall be made by reference to the applicable collective agreement or, where there is no applicable collective agreement, in accordance with national law, collective agreements or practice."
"The approach to causation is further qualified by the principle that the event or factor alleged to be causative of the matter complained of need not be the only or even the main cause of the result complained of, though it must provide more than just the occasion for the result complained of. 'It is enough if it is an effective cause:' Banque Bruxelles Lambert SA v Eagle Star[1995] QB 375 , 406 E-F (CA)."
"The Tribunal then had to consider the Reg 5(2)(c) [sic. 5(2)(a)] test – "on the grounds of" [sic. 'on the ground that'] – reflecting the use of the word in the Framework Agreement 'solely'. The Tribunal is bound by the decision in Gibson v Scottish Ambulance Service – an unreported decision in 2004 in which the Court of Session [sic. EAT. Lord Johnston] held that "on the ground" was not the 'but for' test. A Tribunal had to be satisfied that the reason in the mind of the employer for the difference of treatment between a part-timer and full-time worker was that the part-timer was a part-time worker. The question simply was why did the Respondents treat the Claimant in the way they had. If there was a discriminatory reason then the treatment was unlawful."
"In respect of employment conditions, part-time workers shall not be treated in a less favourable manner than comparable full-time workers solely because they work part time …"
"Clause 4 … precludes part time workers from being treated less favourably than comparable full-time workers on the sole ground that they work part time …"
"It was not suggested that the 2000 Regulations went further than the Directive in conferring protection on part-time workers or were intended to do more than to bring United Kingdom law into line with Community law."