During the rule of Charles II, a crisis broke out when it was discover James, Duke of York (James II and VII), was a Roman Catholic. Parliament tired 3 times to remove him from the line, and put in place Charles's illegitimate – but Protestant – son, the Duke of Monmouth. However, Charles II dissolve Parliament again, and again, stopping the bill from being passed.

But want if it did pass? If Charles gave in, and allow exclude Parliament James and the Duke of Monmouth to become King?
After all the concessions he and his predicessors had already given to Parliment over the traditional personal perogatives/privlages of the monarchy? Handing them the right to decide the heir to the point of plucking one that wasn't even a legitimate member of the household would be a capitulation of the Crown as a politically independent entity. After all, if Parliment can just strongarm distasteful candidates out of the line of succession, then how could a perspective heir be able to adopt personal stances that run counter to the prevailing opinion of the elite of the day?