Lawyers should be able to put questions to some witnesses appearing before Commons committees to help stop MPs probing issues such as phone hacking looking like "junior Perry Masons", Tom Watson said tonight.
Parliamentary select committees should also have tougher powers to tackle people who refuse to attend hearings, the Labour MP suggested.
In a speech to the Hansard Society, the former minister also revealed he had been "99% certain" he was going to stand down ahead of the 2010 election but remained to see out the hacking investigation.
Mr Watson defended the Culture, Media and Sport committee he sits on over its performance at some of the most high-profile hearings during the Westminster inquiry into phone hacking, saying it has very limited resources.
Referring to one article in a national newspaper that had dismissively described the committee members as "junior Perry Masons" - in reference to the television legal drama - he said the journalist had "got a point".
"When you are trying to get facts out of people who don't really want to give you that information, I think there is a case to say that select committees should be supplemented with professional legal advocates who perhaps could put some of the questions on behalf of the committee or help members with their question plan so they can co-ordinate the way they do their questions."
Mr Watson said current sanctions available to force witnesses to appear were "pretty limp".
"Had the summons been refused, I don't think there is a lot we could have done to compel Rupert and James Murdoch to give evidence."
Mr Watson said he quit as a minister in 2009 after The Sun had "smeared" him by carrying incorrect reports which had damaged his reputation. That had taken an "unbearable toll" on his personal and family life, he added.
"There was a quality of life decision to be made and I didn't want to be a target anymore."
He added that in 2009 he had been "so thoroughly sick of the whole system" he was "99% certain" he was going to stand down but his "obligation" to phone hacking victims motivated him to stand again.
Mr Watson used his speech to describe how important the Freedom of Information Act was in the phone hacking investigation.
He said that he wanted to see the Labour Party defending the Freedom of Information Act and added he would like to see a manifesto commitment to extend the scope of the act and give additional obligations to public institutions to answer queries in good time.
He said the act had been particularly helpful in uncovering details of the relationships between members of News International and the Metropolitan Police and Crown Prosecution Service (CPS).
He said: "The information we requested revealed a too cosy relationship between newspaper and police elites. They met socially as well as professionally."
He said the information disclosed revealed then Assistant Commissioner John Yates had five lunches with News of the World and News International and "spent more time lunching with them than he did in deciding not to follow up the Guardian articles with a new inquiry (into phone hacking)".
Mr Watson said his Freedom of Information request into the hospitality register the former Met assistant commissioner Andy Hayman was "similarly alarming".
He said: "He had a dinner with the News of the World at the time of the original police investigation. I thought that was particularly shocking."
He said FoI requests about the CPS helped uncover a "similarly interesting story".
Mr Watson added: "Freedom of Information exposed that there appeared to be, in my view, an inappropriate relationship between News International and senior members of the CPS."
He said then director of public prosecutions Lord Ken Macdonald attended the Society of Editors as a guest of News International executive Les Hinton and failed to declare it in his hospitality register.
"Alarm bells started to ring at this point," he said.
"During a six-week period when the Met was consorting with the CPS on possible offences at the time over Glenn Mulcaire and
Clive Woodward the former Director of Public Prosecutions met with representatives of News International twice...Not only did I believe these meetings to be wholly inappropriate given the CPS was consorting on charges at the time, but they would never have come to light without the Freedom of Information Act."
Mr Watson said the current FoI Act contained too many exemptions that were often used as a defence for non-disclosure.
"The balance in my view is too heavily skewed in the favour of the authorities rather that the person asking for information," he said.
He said the administration required was currently too problematic and the information commissioners office had too few staff, meaning people had to wait a long time for their information.
Mr Watson added that the ministerial right to veto must be abolished. "I know it is uncommon to let go of his powers but it should be ditched," he said.
He said they would never had made progress in exposing the scandal if the FoI Act had not been at their disposal.
Addressing the future of newspapers when the Leveson Inquiry is over he said: "The Press Complaints Commission is such a diminished institution. We cannot do this on the basis of reforming the PCC. I have not met Lord David Hunt (the new chairman of the PCC), people tell me is is a decent man, but he is trying to breathe life into a dead parrot, in my view. The PCC has got to go."
It is important to still have an assertive free press, Mr Watson said. "We cannot have politicians at the helm. I think the real answer lies with ethics and the training of journalists."
The MP suggested there should be an equivalent of the Hippocratic Oath in journalism training.
"Had there been some sort of code of ethics, some no-go areas, around the News International newsrooms then those cub reporters might have been able to stand up to their bosses when they were making them do things that were very bad."