A "FURIOUS" Gordon Brown threatened to destroy Rupert Murdoch's empire after The Sun switched its support to the Conservatives, the Leveson Inquiry heard yesterday.

Former editor Kelvin MacKenzie said Mr Murdoch told him he had received a phone call from the Prime Minister who "roared" at him "for 20 minutes".

However, the comments were dismissed by a spokesman for Mr Brown, who said they were "completely untrue" and "no such words were used and no such conversation took place".

Mr McKenzie, who led The Sun from 1981 to 1994, defended his "bullish" approach to editing and told the inquiry he did not spend much time worrying about journalistic ethics.

"I didn't spend too much time pondering the ethics of how a story was gained nor over-worry about whether to publish or not," he said in a statement.

"If we believed the story to be true and we felt Sun readers should know, we published it and we left it to them to decide if we had done the right thing.

"They could decide we were correct and carry on purchasing us – in my time in ever-increasing numbers – or decide we were wrong, in which case they could decline to buy us again."

The inquiry also heard Mr MacKenzie stood by comments from October, when he said: "My view was that if it sounded right it was probably right and therefore we should lob it in."

He said he had looked up the definition of the word "lob" and found it meant "to throw in a slow arc".

"The point I'm making is that we thought about something, and then put it in," he said.

Mr MacKenzie added that the culture at The Sun had changed under its recent editors, and admitted he himself became "less bullish" towards the end of his time in charge.

"The editors are more cautious and were probably, in a changing world, right to be cautious," he said.

The first session of the inquiry since Christmas also heard from current editor Dominic Mohan, who said the paper could be a "force for good" through its campaigns, support for charities and efforts to explain complicated stories in a clear way.

Prime Minister David Cameron set up the Leveson Inquiry last July in response to revelations that the News of the World commissioned a private detective to hack murdered schoolgirl Milly Dowler's phone after she disappeared in 2002.

l Elisabeth Murdoch is set to follow in the footsteps of her father and brother and deliver the MacTaggart Lecture at this year's Edinburgh Television Festival, according to reports.