Most employers are aware of the rule that an employee on maternity leave is entitled to be offered alternative employment "where there is a suitable available vacancy".

The conventional interpretation in the UK is that the effect of the regulation means that in such competitive situations the woman on maternity leave is given priority.

We think that conventional interpretation of the rule is challengeable.

It is unlawful positively to discriminate in favour of men or women. If a male employee was to lose out on the opportunity of competing for a vacancy because of a priority given to a woman on maternity leave he might well complain of unlawful sex discrimination and be successful.

The prospect of sustaining this argument has improved considerably since the publication of the EAT judgment in Eversheds v de Belin (please click here). There, Eversheds had one position and two lawyers (de Belin - male - and Reinholz - female and on maternity leave.) They had a set of selection criteria to separate the two individuals. The criteria themselves were unobjectionable, and some depended on benchmarks for good case management and – unsurprisingly! - good billing practice. The difficulty was that Ms Reinholz's absence meant that no recent statistics were available for her.

Eversheds had to intervene in some way to allow the comparison to take place. Cliché or not, you could say they had to level the playing field. Unfortunately, in the eyes of the EAT they overdid it and ended up unfairly tipping the balance too much in favour of Ms Reinholz by notionally awarding her full marks for the billing criterion. That was enough to edge out de Belin. When he complained of sex discrimination Eversheds attempted to defend their approach by relying on what they read as their pre-eminent duty to protect the maternity leaver.

De Belin won his claim by showing that there were other (more fair and less discriminatory) methods which Eversheds could have used to level the pitch. As examples, his counsel suggested that Eversheds could have omitted the billing criterion altogether, they could have used a time period during which they were both at work or they could have given her the average score of those in the pool rather than awarding her full marks.

The key quotation from the judgment reads:

"To the extent that a benefit extended to a woman who is pregnant or on maternity leave is disproportionate, we see no reason why a colleague who is correspondingly disadvantaged should not be entitled to claim for sex discrimination…Quite apart from the matter of principle, it is important not to bring into disrepute the legislation which protects pregnant women and those on maternity leave by giving it a wider scope than is properly required."