The great thing about this arrangement is that no matter how you feel about the prime minister of the day, you can be loyal to the Crown, as embodied by whomever the prime minister has appointed to the job. (macleans.ca)
In 2003, US President George Bush memorably labelled Australia America's «deputy sheriff» and this nomenclature was implicitly reciprocated by John Howard, Prime Minister of the day. (blog.politics.ox.ac.uk)
That's a decision for the prime minister of the day. (totalpolitics.com)