Standards in Public Life

Let me go back to the fact that the Prime Minister can say no to the initiation of an independent investigation. What happens if the independent investigator asks the Prime Minister to publish his reasons? Is the Prime Minister compelled to do that? Similarly, given that the Prime Minister has said all along that no rules were broken, what is to stop him breaking rules in the future and saying, “No, we don’t need an investigation because I can assure you that no rules have been broken.”? Where are the checks and balances there?