The Sun's decision to back the Conservative party in the 2010 general election was not taken by Rupert Murdoch, but was a "group decision", the editor of the paper has told the Leveson inquiry.

Dominic Mohan told the inquiry that the proprietor of what is arguably Britain's most influential paper at election time supported the decision but was not solely responsible for it.

Asked why the paper switched its allegiance to the Tories during the 2009 Labour conference, he said: "I think for some time we felt that perhaps … it was time for a change. We certainly sensed that among our readers and I think I reflected that." Mohan told Leveson that the Sun was always good at capturing the "zeitgeist" of the nation and felt it was the right thing to abandon Gordon Brown and switch to David Cameron.

Robert Jay QC, counsel to the inquiry, asked Mohan: "Did he [Murdoch] support the change of allegiances or not?"

Mohan replied: "I believe he did. Yes."

Questioned at the inquiry, Mohan gave the impression that the man who has been courted by a succession of prime ministers including Margaret Thatcher and Tony Blair because of the perceived influence of the Sun during general elections was no longer in the driving seat.

Asked by Jay whether the idea of changing sides was Murdoch's or his, Mohan replied: "I mean, it was a group decision. Me and my fellow executives felt that was the right way to go and we made our feelings known to Mr Murdoch."

Mohan painted a picture of a proprietor who is not as hands-on as in the past and who would sometimes go months without talking to the paper's editor.

"Sometimes he might ring several times a week, other times I might not hear from him for a month or two," Mohan added.

The level of communication was in stark contrast to that which Murdoch had with Mohan's best-known predecessor, Kelvin MacKenzie, who told Leveson earlier on Monday he spoke to him virtually every day. David Yelland, another former editor of the Sun, told the inquiry in written evidence that he would talk to Murdoch "once a week or every two weeks".

MacKenzie edited the Sun for 13 years from 1981 and has remained extremely close to the proprietor, telling Leveson that Murdoch had disclosed to him the content of a conversation he had with Gordon Brown following the paper's decision to switch allegiance in September 2009.

The paper delivered the blow to Brown the day he was to make a conference speech that aimed to regain the political initiative and retain the Sun's support for Labour.

Instead the paper declared "Labour's lost it" on its front page, with a subhead stating: "After 12 long years in power this government has lost its way. Now it's lost the Sun's support too."

MacKenzie said Murdoch told him that a "furious" Brown had phoned the News Corporation founder and threatened to "destroy" his empire.

He revealed last October that Murdoch was in New York when he took the called from the then prime minister, who, "in Rupert's words, 'roared at me for 20 minutes.' At the end Brown said, 'You are trying to destroy me and my party. I will destroy you and your company.'" He confirmed this story to Leveson on Monday.

Mohan, by contrast, had less to offer the inquiry about Murdoch's passion for British politics and the Sun. Murdoch "has never tried to interfere" in the editor's decisions, he said, but that when they talked he would ask "about a range of issues" and particularly what was going on the front page that day.

One recent story that grabbed Murdoch's attention was the coverage of the John Terry race row, said Mohan. He would also ring to discuss internet traffic for the Sun's online operation. "[On] other occasions we might talk about the Sun's digital products, the iPad app – he's often annoyed about how long it takes to download."

MacKenzie used the inquiry to deliver a ferocious attack on previous evidence from former breakfast TV presenter Anne Diamond, who he said was "a devalued witness".

Last year, she told the inquiry that Rupert Murdoch's former butler had said the Sun proprietor had told his editors to "go after" her after she asked Murdoch at a meeting how he slept at night knowing his newspapers were ruining people's lives.

"Over 13 years working with Rupert Murdoch, he never said go get anybody," said MacKenzie. He added: "The butler would not know Mr Murdoch better than I have. I have worked with Rupert Murdoch pretty closely now for 30-odd years, he has invested in my company; I have worked for him; I have taken phone calls from him every single day."

The Leveson inquiry was dedicated to current and former Sun staff on Monday who were grilled about paparazzi, regulation and the impact of the internet.

• MacKenzie said that News International should have been fined for "lying" to the Press Complaints Commission about the extent of phone hacking at the News of the World.

• On regulation, Mohan said the PCC should have a "firm mediation" service to resolve complaints quickly. He said statutory regulation filled him with fear because it would be open to abuse.

• On phone hacking, Mohan said remarks he made in 2002 thanking "Vodafone's lack of security" for the rival Daily Mirror's exclusives was a joke. "It was a cheap shot at the Mirror, attempting to undermine their journalism because they had a particularly good year," he said.

• Two other key staff – the paper's royal editor, Duncan Larcombe, and its showbusiness editor, Gordon Smart – told the inquiry they had no knowledge of phone hacking.

• Larcombe told how two men who stole a memory stick from Pippa Middleton's car were rumbled after they tried to sell photographs they found of the Duke and Duchess of Cambridge to the Sun in 2008. When the thieves discovered the photographs they rang the Sun asking for £25,000.

• The paper's picture editor, John Edwards, defended the decision to send photographers to camp outside the door of the mother of Hugh Grant's baby.

• Edwards expressed regret about the media scrum that awaited Madeleine McCann's parents when they returned home shortly after the disappearance of their daughter in Portugal. He said in future there should be rules limiting the press to one pooled photographer and one TV camera operator.

David Cameron would attend the Leveson inquiry into press standards if summoned to give evidence, Downing Street said on Monday night, responding to reports that Lord Justice Leveson is "99.9%" certain to call him for questioning under oath about his dealings with senior media executives and Murdoch.

A spokeswoman for No 10 said: "A request has not yet been received. If asked, the prime minister would of course attend." Brown is also widely expected to be called, as is the current leader of the Labour party, Ed Miliband.

Cameron is expected to be asked about his decision to employ Andy Coulson, the former editor of the News of the World, as his spokesman.