>... check on abuse of government power. The Queen's consent in forming government is routine but it can be withheld...

> Australia had an example of this where the Governor General (the Queen's representative in the Australian government) sacked the government and formed a caretaker governmen tin the 1970s.

Australia was ruled by a Liberal/Country coalition from the 1940s to the end of 1972. Finally the workers of Australia elect a Labor PM, and he was thwarted for three years and then removed at the behest of a hereditary monarch thousands of miles away. That sounds like abuse, but not of the type you mean.