There is no legal definition of what will amount to being in the public interest but in practice, generally, this means that a disclosure cannot relate to a purely personal matter.
The Employment Tribunal have confirmed in recent cases that it is not enough for there to be more than one person’s interest at stake and that there are several factors to be considered when making an assessment as to whether a disclosure is in the public interest. For example:
The number of individuals whose interests the disclosure served;
The extent to which those interests are affected by the wrongdoing disclosed; and
The identity of the alleged wrongdoer.