London (CNN) -- A former Rupert Murdoch newspaper editor who became a spokesman for British Prime Minister David Cameron told a probe into British press ethics that he did not know about phone hacking while he was editor.
Andy Coulson was quizzed Thursday over the News of the World's relationships with politicians, as well as his role as Cameron's communications chief, in two-and-a-half hours of questioning before the independent, government-appointed panel.
The Leveson Inquiry was set up in response to accusations of widespread phone hacking by journalists working for the News of the World, which was edited by Coulson from 2003 until his resignation in 2007.
Critics have questioned Cameron's judgment in hiring Coulson after he quit the paper.
Coulson resigned as Cameron's spokesman in January 2011 when police opened a new investigation into the scandal. He insisted he was innocent but said he had become a distraction for the government.
Questioned Thursday, Coulson said the jailing of two News of the World employees over phone hacking in 2007 did come up in discussions with senior party members before he was offered the job.
He told the inquiry he had told them and Cameron what he has said repeatedly -- that he knew nothing about the practice of hacking under his leadership of the paper.
He also denied he was taken on because of his links to News International, the British arm of News Corp., which runs the UK's biggest selling daily tabloid, The Sun.
Coulson said he had told Cameron and then-shadow chancellor George Osborne that his connections would not guarantee the backing of Murdoch's papers, and that they should reach out to a wide range of news outlets.
The Sun switched its allegiance from the Labour Party to Cameron's Conservatives ahead of the 2010 election, which resulted in the formation of a Conservative-Liberal Democrat coalition government.
Coulson said he never witnessed a conversation that was "inappropriate" between members of the government and News International.
He also denied direct involvement in discussions of News Corp.'s bid fully to take over British satellite broadcaster BSkyB, and dismissed as a conspiracy theory the suggestion that some kind of deal had been struck by the Conservatives on that takeover in return for Murdoch's support.
Asked later however whether politicians and the press were too close, Coulson said he was "not minded to disagree" with the assessment of Cameron that relations were "too cozy."
Coulson said he had continued to hold £40,000 ($64,000) of shares in News Corp. while working for Cameron in opposition and in government, but had not considered it a conflict of interest.
He had not paid much attention to his financial affairs, he said, because his job kept him very busy.
Quizzed about his relationship with Murdoch, chairman of News Corp., Coulson said the media baron would often call on a Saturday night, shortly before the newspaper's publication Sunday.
"We discussed politics generally. He would give me his views on whatever was in the news at the time," Coulson said.
Coulson said Murdoch was supportive of him as an editor.
"I was an employee, and I thoroughly enjoyed my time working for him. In the interactions I had with him, he was warm and supportive," Coulson said. "I wasn't particularly close to him, I wouldn't want to overstate it."
Coulson said the newspaper tended to reflect the public mood on politics rather than try to lead it, except on certain issues.
The decision to support Labour Prime Minister Tony Blair in the 2005 election was taken with the News of the World's editorial team, he said. However, he did not recall discussing the paper's support for the Labour Party with Murdoch.
"I was determined we would spend a reasonable amount of time with politicians from both parties and make up our own minds," Coulson said.
The paper's coverage of the Conservative Party leadership contest, which resulted in Cameron becoming party leader, was not skewed in favor of any of the candidates, Coulson said.
Asked if the News of World's coverage of the Conservative Party grew more favorable after Cameron became leader, Coulson pointed out that the paper had run stories that did not help the party.
He resigned as editor when one of the paper's journalists and a private investigator were sent to prison for phone hacking in 2007, although he denied knowing about the illegal eavesdropping.
Six months later, he was hired to work for Cameron as his director of communications. Coulson said the progression from the media world to politics was not unusual.
Questions have been raised in the UK media about the level of security vetting Coulson underwent. He told the inquiry he had seen some classified documents and occasionally attended security briefings.
The phone hacking scandal has reverberated throughout the top levels of British politics and journalism, and led a parliamentary committee to issue damning criticism of global media baron Murdoch.
Dozens of people, including Coulson, have been arrested in connection with the scandal, although no one has been charged. He is free on bail.
Another former News of the World editor, Rebekah Brooks, is set to appear before the inquiry Friday.
Brooks resigned last summer as chief executive of News of the World's publisher, News International, a subsidiary of News Corp., amid outrage over claims of widespread hacking by the Sunday tabloid's staff.
She was editor of News of the World in 2002 when the newspaper hacked the voice mail of a missing schoolgirl, Milly Dowler. The teenager was later found dead.
Brooks has been arrested twice and released on bail in connection with police investigations into the scandal.
Coulson acknowledged that Cameron was particularly interested in gaining the backing of The Sun, the biggest-selling daily tabloid and another of Murdoch's UK newspapers.
But he denied having encouraged Cameron to become friends with Brooks, who was The Sun's editor from 2003 to 2009.
Coulson said there was a long-standing family connection between Cameron and her husband, racehorse trainer Charlie Brooks, and the couple lived near the Conservative lawmaker's constituency home.
Rebekah and Charlie Brooks have socialized with Cameron. Rebekah Brooks is also known for close ties to Murdoch.
Last month, the Leveson Inquiry grilled the media magnate and his son, James Murdoch, also a senior News Corp. executive.
Rupert Murdoch faced stinging criticism last week when a UK parliamentary committee examining phone hacking at the News of the World said he was "not a fit person" to run a major international company.
However, News Corp.'s board of directors strongly endorsed him Wednesday, expressing "full confidence in Rupert Murdoch's fitness" and supporting his leadership of the company.
Murdoch's News Corp. encompasses Fox News, The Wall Street Journal, the New York Post, and Harper Collins publishers in the United States. News International -- a British subsidiary of News Corp. -- owns The Sun, The Times and The Sunday Times in Britain.
CNN's Laura Perez Maestro contributed to this report.