King Charles and Prince William are said to be really frustrated over the legal complications preventing removal of Andrew from the British royal line of succession.
Andrew, who stepped back from royal duties after controversy linked to his association with disgraced financier Jeffrey Epstein, is eighth in line to the throne despite losing his honorary titles and royal roles.
According to OK! Magazine, the monarch and the Prince of Wales tried to find a way to remove him from the succession.
However, after it was revealed that there is no clear legal precedent to do so, they have now stopped but it is increasing their frustration.
"There is a palpable sense William and Charles are seething and frustrated behind the scenes over the labyrinthine complications stopping Andrew being axed from the line of succession, because while the public mood is clear, the legal reality is just proving far too extraordinarily difficult to navigate,” the source said.
They added, "They would love to see swift action, but the system itself is so complex that even beginning that process raises questions that do not have straightforward answers."
Speaking on it, a parliamentary source said, "There is ongoing work to understand whether it is even feasible to remove him as an individual without triggering wider constitutional consequences.
“That uncertainty is part of what is fueling the frustration at the highest levels. But it is not simply a matter of political will – it is about untangling centuries of legal precedent."
An insider also noted that this is not a “domestic issue” as it “would require coordinated legislative changes across multiple independent nations.
“In practical terms, it risks becoming what many have described as a global mess."
"That is at the heart of why William and Charles are so angry – they are confronted with a situation where the desire for change collides with a constitutional framework that is incredibly rigid."