The ECJ has held that Spanish legislation permitting employees to take time off to feed a baby breaches the Equal Treatment Directive. In Spain, female employees are allowed to take time off work to feed a baby under nine months of age. This right was originally introduced in 1980 in order to promote breastfeeding but it has since been amended by case law to cover bottle-feeding. By statute the right can also be exercised by male employees, but only if the mother qualifies for the right.

In March 2005, Mr Alvarez asked his employer if he could take time off to feed his child, but his request was refused because the child's mother was self-employed and therefore did not qualify for the right. The ECJ held that this was discriminatory on the grounds of sex as between employed fathers and employed mothers. For male employees the fact of being a parent was not sufficient to gain entitlement to leave, whereas for a female employee it was. The ECJ took the view that once this leave was extended to cover bottle feeding, something that either parent could do, it was no longer appropriate to see it as specifically for the protection of new mothers. Instead it was granted to workers in their capacity as parents (Roca Alvarez v Sesa Start Espana ETT).

Whilst there are no parallel provisions in UK law, it has been suggested that this case may have an impact upon other areas, particularly the provision for additional paternity leave (APL) which will apply in respect of babies due on or after 3 April 2011. If additional maternity leave (AML) is effectively to become "transferable" to the father in the form of APL, this case suggests that it will no longer be possible to justify different treatment of men and women on the grounds that AML is for the protection of new mothers. Following the ECJ's reasoning, the leave is not exclusive to women, and so is granted to workers in their capacity as parents. This may open up the way for fathers on APL to argue for the same benefits from their employer as would be received by mothers on AML.