Lord Justice Leveson has launched a into media standards and ethics, denying he has any "hidden agenda" to inhibit the press.
In a 20-minute opening statement on Monday morning, Leveson denied he had tried to "gag" education secretary Michael Gove following a speech about the inquiry creating a "chilling atmosphere" towards freedom of expression.
But Leveson confirmed he did make a call to the cabinet secretary, Sir Jeremy Heywood, in February following Gove's speech to question whether David Cameron still supported the judicial inquiry the prime minister established in July last year in response to the News of the World phone-hacking scandal.
He was concerned that comments made by Cameron at prime minister's questions indicated he supported Gove.
"I was concerned about the perception that inquiry was being undermined while it as taking place," Leveson said.
Leveson was responding for the first time publicly on Sunday on June 17 headlined "Leveson's threat to quit".
He did not deny or confirm this aspect of the story but said the Mail on Sunday had made "very serious allegations".
During PMQs in February, Cameron said Gove had made "an important point" in his speech, adding: "Even as this inquiry goes on, we want to have a vibrant press that feels it can call the powerful to account, and we do not want to see it chilled."
On Monday, Leveson said: "It seemed to me at the time that … the PM's response was open to the interpretation that he was indeed agreeing with Mr Gove's views … Of greater concern to me was the question whether what he said had become the government's position to not just the effects of the inquiry, intended or otherwise, but also that there was a danger that I had an interest in taking over as arbiter of what a free press should be."
He added that he thought it "necessary and appropriate" to make the call to Heywood. "I received the assurance that no fixed view had been formed," he said.
The appeal court judge also fired a shot across the bows of critics, warning that he would not be blown off course by attacks on the inquiry.
"I was not be deterred from seeking to fulfil the terms of a reference that have been set for me," Leveson said.
He insisted he remains open-minded about the future regulation of the press and understands the "anxieties of editors".
"Every exchange you have with a witness will be analysed and considered in order to reveal a hidden agenda. There is none," he said.
Simon Walters, the political editor of the Mail on Sunday and co-author of the 17 June story, will appear before Leveson on Monday afternoon, raising the prospect of tetchy exchanges with the judge.
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