Can grandparents be denied contact if a parent has a good reason to keep them away?

Yes. A parent's decision to limit or refuse a grandparent's contact carries real weight, and where a parent has a genuine, well-founded reason - such as a documented safety concern, a pattern of the grandparent undermining the parent's authority, or conduct harmful to the child - a court is likely to support that decision rather than override it. The best-interests test doesn't treat grandparent contact as an entitlement that overrides a fit parent's reasonable judgment about who spends time with their child.

That said, a parent's reason has to be more than a general preference or an unresolved conflict with the grandparent that has little to do with the child's welfare; a court will look at the actual evidence behind the parent's decision, not simply accept an assertion that contact isn't wanted. Where the parent's stated reason doesn't hold up to scrutiny, or where the grandparent can show the relationship genuinely benefits the child despite the conflict, a court can still order some form of contact, sometimes on a limited or supervised basis. Both sides benefit from focusing evidence on the child's welfare specifically, rather than on the adults' relationship with each other.