When most of the evidence heard by the Leveson Inquiry has faded from the memory, a phrase that will linger is "country supper". It was included in the text sent to David Cameron by Rebekah Brooks, then the chief executive of News International, the day after George Osborne had delivered a speech to the Conservative Party conference in which he proclaimed: "We're all in this together."

The Chancellor meant to convey that everyone in the UK was "in this together" as the Government grappled with the consequences of recession, but, to judge by Mrs Brooks's text, the people who were in it together were the members of the elite social circle centred on David Cameron. As well as looking forward to "country supper" with the Prime Minister, Mrs Brooks's message said: "I'm so rooting for you tomorrow not just as a proud friend but because professionally we are definitely in this together."

As this newspaper has said before, Leveson has many flaws. One was on display yesterday as Lord Justice Leveson and Robert Jay skirted around the issue of David Cameron's decision to employ the former News of the World editor Andy Coulson. The Prime Minister admitted that this was a "controversial" appointment that had "come back to haunt him and me". He admitted also that the police and others had questions to answer about why phone hacking could go on for so long without being properly investigated.

It might have been enlightening if he had been asked whether reluctance on the part of the police to pursue the hackers was linked to a political culture in which a tabloid editor who has resigned under a cloud could move so quickly into so powerful a position at the Prime Minister's side. But Lord Justice Leveson and Mr Jay had to take care because of the risk of prejudicing any trial that might arise from the phone-hacking scandal.

However, something the Inquiry undoubtedly has achieved is to expose to the light the chummy relationship between government ministers and the Murdoch organisation. It was during that part of the questioning that David Cameron looked seriously uncomfortable yesterday – while he was clearly relaxed as he tore apart the "conspiracy theory" expounded by his predecessor Gordon Brown.

It has been a very long inquiry – and it is not over yet – and yesterday Mr Cameron may have experienced a twinge of regret that he ever called it in the first place. Prime Ministers set up inquiries such as this one to get themselves out of a hole, but, once they have been set in motion, there is no telling where they may go.

The initial purpose of the Leveson Inquiry was to look into phone hacking, which is a criminal activity. By now, there is not a journalist in the country who is not aware of the possible consequences. Meanwhile, the Inquiry's reach has grown ever wider to cover virtually any aspect of the relationship between newspapers and the politicians, celebrities and others they write about.

When it is over, Lord Justice Leveson and his panel may feel that to justify the time and expense involved, they must come up with substantial recommendations, which curb the press and produce the paradoxical result that an exercise in openness leads to a less open society. We can only hope that they prove wiser than that.