The judge heading Britain's inquiry into press ethics has complained to the country's top civil servant after a government minister said his probe was having a "chilling" effect on free speech, The Mail on Sunday newspaper reported.
Lord Justice Brian Leveson remonstrated with Cabinet Secretary Jeremy Heywood over the claims made by Education Secretary Michael Gove, the tabloid said.
Leveson telephoned Heywood to warn him that the inquiry into the culture, practices and ethics of the press risked being undermined by such outbursts, the report said.
The Mail on Sunday quoted a government source as saying: "Our clear impression was that he was spitting tacks with Gove and was ready to resign unless the minister was told to shut up.
"Leveson said that if this was going to continue with Cabinet ministers offering opinions while the inquiry was in its early days, he would have to question whether the inquiry had any value, bearing in mind it was using public money.
"He did not threaten to resign."
The BBC said it too understood that at no point had Leveson threatened to quit.
Gove, a former journalist for The Times, one of media baron Rupert Murdoch's British newspapers, told an audience of political reporters in February that the Leveson Inquiry had created a "chilling atmosphere" towards freedom of expression.
It was set up by Prime Minister David Cameron in July last year following revelations that Murdoch's News of the World tabloid hacked into the voicemails of a murdered schoolgirl.
Saying any past misdemeanours were covered by existing laws, Gove said any attempt to toughen regulation could result in "a cure worse than the original disease."
"When an undoubted wrong has been done there's a desire to find a judge, a civil servant, a representative of the great and good, inevitably a figure from the establishment, to inquire into what went wrong and to make recommendations about what might be put right.
"There is a danger we may see judges, celebrities, and the establishment, all of whom have an interest in taking over from the press as arbiters of what a free press should be, imposing either soft or hard regulation.
"What we should be encouraging is the maximum amount of freedom of expression."
When Gove testified before Leveson on May 29, he repeated his claims and the pair clashed.
The judge told him: "Mr Gove, I do not need to be told about the importance of freedom of speech, I really don't."
He said he was "concerned" by Gove's view that "unacceptable" behaviour has "to be accepted because of the right of freedom of speech".
Last week he opened hearings by warning it was "essential" that cross-party political support for his investigation was "not jeopardised".
Cameron's Downing Street office, Gove and the Cabinet Office, where Heywood works, all declined to comment.
A spokesman for the inquiry said: "Lord Justice Leveson is conducting a judicial inquiry and, in that capacity, will not comment on press stories outside the formal proceedings of the inquiry."