We know from survey data in the U.K., Ireland, and the U.S. that over 90% of workers will normally report inside their organization. As Tom said, people want to be given the opportunity to report through line management and through the relevant channels internally before they feel forced to go outside the organization.
In Ireland, a whistle-blower can go outside the organization in situations where it's considered to be reasonable, where they believe, for example, that they may suffer as a consequence from speaking up internally, or where that information may be covered up. They are afforded the opportunity to report to a member of the media or a member of Parliament. In situations where the information is related to serious wrongdoing, they will be protected when reporting it to a journalist.