Does a grandparent need the consent of both parents, or just one, to start a contact case?

A grandparent doesn't need either parent's consent to start a contact application - a non-parent can bring their own application to the family court seeking contact regardless of whether one, both, or neither parent supports it. Requiring parental consent as a precondition would defeat the purpose of the process, since these applications typically arise precisely because at least one parent is limiting or opposing contact.

What parental consent, or the lack of it, does affect is how the case actually unfolds: if one parent supports the grandparent's contact, that parent's evidence and position can meaningfully strengthen the application, and the case may be less contested overall. If both parents oppose contact, the grandparent faces a harder case, as discussed elsewhere, but not one that's barred outright - the court still applies the same best-interests test regardless of how many parents object. Either way, both parents are entitled to be notified of the application and to participate in the proceeding, since a decision about a child's contact with a third party affects them directly. A family lawyer can guide you through starting the application regardless of the parents' positions.