David Cameron's bad misjudgement that it's "fair enough" for Prince Charles to enjoy private contact with ministers is leading to a bigger problem: the government is now on course to steal power away from the courts.
That threat is now emerging after today's judgment from Lord Neuberger, the culmination of a ten-year campaign by the Guardian newspaper, forced the prime minister to accept the government must now consider how to release the 27 'black spider' letters written by the heir to the throne in 2004 and 2005.
It's bad enough, on a grim day for the government, that Cameron can be so assured as he insists it's acceptable for the Prince to have had any contact with ministers at all.
"This is about the principle that senior members of the royal family are able to express their views to government confidentially," the prime minister said.
"I think most people would agree this is fair enough."
That basic assumption clashes with the views of those who've told Politics.co.uk in the past they feel that politics and the monarchy should be completely separate.
Graeme Smith, chief executive of Republic, claimed: "Charles is abusing his position to promote his own interests and his pet issues. Such dishonesty needs to be directly challenged by MPs and in public."
And Tamasin Cave of Spinwatch said: "Prince Charles, if you strip away all the paraphernalia of royalty, is a businessman with multimillion pound business interests.
"When you have people with commercial interests interfering in policy, there needs to be maximum transparency. I wouldn't make any distinction between Prince Charles and his business interests and any other powerful person in this country. If they are speaking to ministers, the public must know."
The government disagrees - and because of that is now setting itself on an alarming collision course with the judiciary.
Lord Neuberger made this point in his judgment:
"A statutory provision which entitles a member of the executive (whether a government minister or the attorney-general) to overrule a decision of the judiciary merely because he does not agree with it would not merely be unique to the laws of the United Kingdom. It would cut across two constitutional principles which are also fundamental components of the rules of law."
And now the prime minister has this to say:
"Our FOI laws specifically include the option of a governmental veto, which we exercised in this case for a reason. If the legislation does not make parliament's intentions for the veto clear enough, then we will need to make it clearer."
It is always the government's prerogative to change the law to get its way. But in making clear that is a possibility in this case, Cameron is threatening to shift the balance of power between the government and the courts.