The Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000 (PTWR), which came into force on 1 July 2000, established a minimum standard of fairness for part-timers so that they cannot be treated less favourably than comparable full-time co-workers, unless the treatment is justified on objective grounds.

In British Airways v Pinaud, the Employment Appeal Tribunal (EAT) considered whether a part-time airline worker whose basic annual salary was 50 per cent of that of a full-time crew member but whose contract stated that she had to be available to work for more than half the number of days required of a full-time employee had been subjected to less favourable treatment on account of her part-time status.

Florence Pinaud had worked full-time as a purser for British Airways (BA) until she returned from maternity leave in 2005, at which point she started to work part-time. Full-time staff worked a pattern of six days on and three days off, meaning that they were available for work for 243 days a year and off for 122 days. Part-time staff worked a pattern of 14 days on and 14 days off. They were required to be available to work for ten days during the ’14 days on period’, meaning that they had to be available for 130 days a year – more than half the available days required of a full-time worker. Because flights were allocated according to a system whereby staff could bid, according to personal preference, to work on longer flights, which might result in additional pay, or shorter flights, and staff were also required to carry out ground duties and undergo training, the actual hours worked could fluctuate and there was no clear link between days of availability and hours or even precise days worked. The annual basic salary did not vary with the number of duty hours, however.

Mrs Pinaud claimed that she had suffered less favourable treatment in two ways. Firstly, her contract of employment required her to be available to work for 3.5 per cent more days than a full-time worker. Secondly, she argued that she was regularly required to work more duty hours than her full-time equivalent. BA denied that the part-time pattern constituted less favourable treatment, but if it did it was justified as there was a legitimate aim to provide a workable 50 per cent contract working pattern. Any differences compared with full-time workers were trivial, resulting as they did from the system of bidding for flights, and were a proportionate means of achieving a legitimate aim.

The Employment Tribunal (ET) found that the 8.5 additional days per annum that a part-time worker was required to be available for work constituted a significant period and did amount to less favourable treatment. Whilst it agreed that there was a legitimate objective – i.e. to provide a flexible and predictable part-time shift pattern that worked for both BA and its staff, this was not reviewed at the time it was introduced to assess whether it may be discriminatory. Additionally, the less favourable treatment could have been eliminated by adjusting the salaries of part-time workers in a different way – for example by paying them 53.5 per cent of the full-time salary. Having reached that conclusion, the ET did not go on to consider Mrs Pinaud’s second claim regarding actual hours worked or the statistics produced by BA in evidence.

BA appealed against the ET’s ruling. The EAT upheld the ET’s decision that the term in Mrs Pinaud’s contract regarding availability for work did offend against the PTWR. However, when it came to the question of justification the ET had been wrong to dismiss the statistical evidence presented as irrelevant. Having accepted that the unfavourable treatment complained of was in pursuit of a legitimate aim, the ET was bound to carry out a practical assessment of the impact of that treatment when deciding whether or not it was appropriate and necessary for achieving the stated aim.

BA had argued that the effect of the unfavourable treatment was insignificant as in practical terms a part-time worker was not required to work more hours than her full-time comparator. This argument needed to be addressed. If the treatment had no impact on the amount of work Mrs Pinaud actually did, it was far from clear that an increase in salary as suggested by the ET was an alternative way of achieving the legitimate aim. Such a solution might be out of all proportion to the disparate treatment.

The case was therefore remitted to a fresh ET to consider the question of justification of the requirement as regards available days and a full examination of the second part of Mrs Pinaud’s claim.