1. The principal issue in this Claimant's appeal is whether an Employment Tribunal sitting at London (South), chaired by Employment Judge Freer, erred in law in holding that the Claimant, Mrs Johal, was not less favourably treated by the Respondent, her employer EHRC, on the ground that she was, at the relevant time, exercising her statutory right to maternity leave when they failed to notify her of an internal job opportunity contrary to section 3A(1)(b) of the Sex Discrimination Act 1975 (SDA) as amended.

1. The Tribunal found that the reason for that treatment was administrative error, not the fact of her maternity leave. Maternity leave was the occasion for the treatment complained of; it was not the cause of the treatment. We here summarise shortly the Tribunal's reasons accompanying their reserved judgment dated 6 October 2009. The Claimant also raises a secondary issue complaining that the Tribunal made no decision on the question as to what were the chances of her securing the relevant position had she been in a position to apply for it. That further issue will only arise for determination by us if she succeeds on the primary liability issue.

1. As Lord Hope of Craighead observed in Anyamu v South Bank Students Union [2001] ICR 391, paragraph 37, the questions of law that have to be determined in discrimination cases are often highly fact sensitive. It is therefore important, before embarking on an analysis of the relevant legislation in the higher courts, to distil from this Tribunal's admirably full findings of fact those primary facts material to the principal question before us.

1. The Respondent was set up to bring together what were formerly the EOC, CRE and DRC (the legacy commissions). The Claimant commenced employment with the CRE as a Personal Assistant (PA) in the Commissioner's Office on 1 April 2002 and in April 2005 became PA to the Director of Corporate and Government Relations.

1. The transfer of employment of employees of the legacy commissions to the Respondent was effected on 1 October 2007. Terms and conditions of employment of staff varied between the three legacy commissions. In order to bring together staff in the new organisation a "team mapping" process was employed as a way of assimilating former legacy commission staff into the new structure. Prior to the transfer date the Claimant was informed, by a letter dated 23 July 2007, that it was proposed that she be allocated to the Commissioner's Office Group Directorate.

1. On 3 December 2007, following the transfer date, the Claimant emailed Danielle Todd of HR, informing her that she wished to take maternity leave from 1 December 2007 until 5 January 2009, subject to subsequent changes. She added:

"[…] I would like to remain on the IT network as I would like to continue to read certain email alerts. In addition I will be grateful if I was kept in the loop with regards to vacancies and training packages within the Commission while I'm away. I look forward to hearing from you and receiving written confirmation in due course of my entitlements and terms and conditions whilst on maternity leave."

1. At that time, in the absence of a line manager in post, Debbie Wood, Director of the Commissioner's Office, was the Claimant's senior and was considering, as part of a potential reorganisation, creating the post of Commissioner's Office Manager. That post, subsequently approved, was a level four position. The Claimant's role was initially evaluated at the lover level two equivalent, although following an appeal that was raised to level three.

1. On 29 February 2008 the Claimant emailed Ms Wood and the IT Service Desk, asking that her work email account, which had lapsed in December 2007, be reactivated. That was done the same day.

1. A team meeting was called for 4 March 2008. On that day the Claimant attended an individual meeting with Ms Wood. The Tribunal found (paragraphs 41 to 43) that at that meeting the Claimant was provided with a new structure chart showing a vacant Commissioner's Office Manager post positioned next to the Claimant's proposed post. Ms Wood explained to the Claimant the need for an Office Manager. The Claimant did not say at that meeting that she was interested in the new Office Manager position; she did say that she wanted to move away from support roles and into a policy role. She did not suggest before the Tribunal that her allocation to a level two role was due to her taking maternity leave.

1. On 5 March 2008 Ms Wood emailed the Claimant, giving her personal assurance to keep her "inside the loop of developments and any job vacancies". Further confirmation was provided by Ms Beresford of HR.

1. On 20 March 2008 Ms Wood received approval to recruit for the Office Manager post and on 4 April 2008 the Claimant emailed Ms Wood, informing her that she had moved to Ireland for the spring and asking for an extension of time for handing in her request for funding for an Further Education course. That late application was approved and, in due course, funding was provided for a Psychology degree course.

1. The Office Manager vacancy was advertised in the summer. The Claimant did not access the website on which the vacancy was posted and, due to administrative error the Tribunal found, the Respondent did not notify her of that vacancy. Consequently she did not apply for the post which was eventually filled by another employee in the office, Jayshree Patel.

1. Following her complaint that she had not been notified of the vacancy while on maternity leave Ms Wood said that she would speak to HR, she having specifically asked that they updated the Claimant on vacancies. The IT Department's Mr Unwin apologised for the breakdown in communication; having reactivated her access it was then disabled again as part of what is described as a tidying up exercise.

1. The Claimant then raised a grievance on 24 September 2008. Her complaint was that she had been overlooked on a promotion opportunity within her directorate. That grievance was initially investigated by Ms Patten. She concluded, in an outcome letter dated 17 December 2008, that it appeared that the Commission aimed high, raising her expectations in terms of communication methods and then failed to deliver on all aspects of that promise. However, Ms Patten also pointed out the Claimant's failure to utilise the link to the recruitment site. The grievance was not upheld. An appeal followed, dealt with by Mr Diamond. He too shared responsibility for the communication failure between the Claimant and the Respondent.

1. The Tribunal noted that another employee, Zoë Mayne, was also on maternity leave. She received job vacancies by post, the Claimant's preferred method, received a link to the recruitment micro site and a range of other communications.

1. Having directed themselves as to the law, including section 3A SDA (at paragraphs 90 to 103) in a way to which Ms Rayner takes no exception, the Tribunal concluded that the Respondent genuinely intended to keep the Claimant notified of vacancies but that there was a breakdown in the administrative system which the Respondent had put in place to keep those absent from work notified of job vacancies (paragraph 113). However, the Claimant could reasonably have done more herself to keep in touch, particularly since she had been made aware by Ms Wood that the Office Manager post was pending.

1. Although she suffered a detriment in not being notified of the vacancy that was not on the ground of her maternity leave; the predominant and effective cause of her non receipt of the information, the Tribunal found, was administrative errors in the Respondent's system. Others on maternity leave received appropriate information. On the specific facts of this case the causative link between maternity leave and the detriment suffered was not made out.

1. Asking the question posed by Lord Nicholls in Shamoon v Chief Constable of the Royal Ulster Constabulary (HL) [2003] ICR 337, why was the Claimant treated in the way complained of? The Tribunal's answer was, due to genuine administrative error, not her maternity leave.

1. In advancing the primary ground of appeal Ms Rayner takes issue first with the Tribunal's use of the expression "predominant and effective cause" (to be found in the judgment of Mummery P in O'Neill v Governors of St Thomas More RCVA Upper School & Ors . At paragraph 94 the Tribunal directed themselves that the prohibited ground need not be the sole or main cause, it is enough if it is an effective cause. She further submits that certain findings made by the Tribunal were, in the legal sense, perverse.

1. Those submissions have been developed by Ms Rayner on paper and in oral argument. We have also had the benefit of detailed argument in response by Ms Stone. Put shortly, we prefer the submissions of Ms Stone. Our analysis is as follows. Section 3A SDA is headed Discrimination on the Grounds of Pregnancy or Maternity Leave. A person discriminates against a woman if on the ground that the woman is, here, exercising a statutory right to maternity leave, the person treats her less favourably.

1. We pause to observe that the statutory definition tails off at that point, the earlier comparison having been removed with effect from 6 April 2008 by statutory instrument. Thus, although the words on their face are apparently meaningless; less favourable treatment necessarily involves a comparison; they should be read in the context of European jurisprudence adopted at the highest level in the domestic jurisdiction, which makes clear that no male comparison can be made with a pregnant woman, or one on maternity leave post birth. The legislation is designed to outlaw unfavourable treatment of women on maternity leave.

1. We have been much assisted by the analysis of Underhill P in Amnesty International v Ahmed [2009] IRLR 884 at paragraphs 31 to 37, which reconciles the approach taken by the House of Lords in James v Eastleigh Borough Council [1990] IRLR 572 and by Lord Nicholls in Nagarajan v London Regional Transport [1999] IRLR 572 and later Shamoon. That analysis by the President seems to us to be supported by the various judgments of the Supreme Court in R v Jewish Free School Governing Body & Ors [2010] IRLR 136, regardless of which side of the five/four divide the Justices of the court fell.

1. In simple terms, where an act is inherently discriminatory, for example, the difference in ages between men and women pensioners entitled to free swimming in Eastleigh Council's pools, the detriment suffered by the Claimant will be on the prohibited ground without more. The discriminator's motive for that discrimination, whether benign or malicious, is immaterial. However, where the act complained of is not in itself discriminatory, as we accept Ms Stone's submission applies in the present case, it may become so by discriminatory motivation, whether conscious or subconscious; the Nagarajan type of case.

1. Thus, the critical question we think in the present case is the reason why question posed by Lord Nicholls: "Why was the Claimant treated in the manner complained of?"

1. This Tribunal posed and answered that at paragraph 131 where they said this:

"The Tribunal considers that the above conclusion is reached however the burden of proof provisions are approached. Whether the above matters are principal findings of fact (in which case step one is not satisfied) or require an explanation by the Respondent (the Claimant's treatment was in no sense whatsoever on the proscribed ground), the same end point is reached. Using the commendably sensible Shamoon approach, as preferred by the Tribunal in the circumstances of this case, the reason why the Claimant was so treated was because of the genuine reason of an administration system error."

1. The short question for us is whether that was a permissible answer by the Tribunal. Despite Ms Rayner's determined argument we accept Ms Stone's submission that, on the facts found, that finding by the Tribunal cannot be impugned on appeal. Our approach is analogous to that of HHJ McMullen QC and members in Culshaw v Eldomian Group Ltd (UKEAT0272/04/DA 30 September 2004) to which Ms Stone referred us. The Tribunal formed a view on the facts to which they were entitled to come.

1. Applying the approach endorsed by the Court of Appeal in Madarassy v Namura International [2007] ICR 867 to section 63A SDA, if it is assumed in the Claimant's favour that a prima facie case of maternity leave discrimination is made out (and Ms Stone does not accept that it is) the Respondent, being required to provide a non discriminatory explanation has done so. It was administrative error, not the fact of maternity leave which was the reason for the Claimant's detrimental treatment.

1. In these circumstances the first ground of appeal fails; the secondary ground is, therefore, rendered moot and consequently this appeal fails and is dismissed.