While journalism students are generally taught ethics, they fear losing their jobs if they refuse to go along with what is expected of them once they enter newspapers, the Leveson Inquiry into press standards heard.
Giving evidence, Professor Steven Barnett from the University of Westminster said: "There's an abundance of people who are keen, eager, quite idealistic about their view of what journalism can do, what they can achieve as journalists, the role of journalism in a democratic society."
But instilling "moral courage" in journalism students for when they enter the workplace is a problem, he acknowledged.
"They're told in no uncertain terms that if they don't do what they're asked to do there's no shortage of young, willing recruits waiting to take up the very valued and rare job that they have," he said.
"I'm talking specifically now about the kinds of national tabloid newspapers where a lot of these problems have occurred."
Those kinds of pressures were not "something we can actually teach someone to deal with", he suggested.
Angela Phillips, who runs the print journalism programmes at Goldsmiths and gave evidence alongside Prof Barnett, said the university's courses taught students to be ethical, "knowing they're going to be going into an industry where they're under constant pressure".
She claimed that some journalists "get trapped" working for tabloids as they pay more than other newspapers, and "kind of go with it" for financial reasons.
The academics, joined by head of journalism at City University London Professor George Brock and Professor Brian Cathcart of Kingston University London, offered a lukewarm assessment of the National Council for the Training of Journalists (NCTJ), with Prof Cathcart noting that "it's a small corner of the NCTJ diploma that addresses ethical questions".
This was perhaps a reflection of the training body being "the servant of the industry, and the industry's priorities not being highly ethical", he suggested.
But Prof Brock, a former managing editor of The Times, said: "How people behave is determined by the culture of a newsroom."
A defence of tabloid newspapers was also mounted, however, with the academics and Lord Justice Leveson at pains to point out their positive sides.
Prof Barnett, a former Observer columnist, said: "There are elements of the way in which some red top newspapers in this country have behaved which are undesirable and need to be prevented, but there's an art and a skill to good tabloid journalism that all of us I think would recognise.
"The issue is getting the best of that while avoiding those egregious excesses that we've seen over the last couple of years."
And Ms Phillips described the tabloids as "really funny a lot of the time", adding: "I don't think we want everyone to be the same as the Guardian, the Telegraph, the Times and the Independent".
Lord Justice Leveson meanwhile said he wanted "to celebrate all that's good about the newspapers, the print media".
He told the inquiry: "I'm not in any sense seeking to beat down either the mid-market or the tabloid press at all. They do, in large part, an enormously valuable job."
The problem, he said, was trying to "draw the line".
Politicians came under fire for failing to do enough to rein in the press and were blamed for some of the newspapers' excesses.
Prof Petley accused them of being too "terrified" of the press to tackle the question of regulation.
"This is not the press being a watchdog, this is the press being an attack dog," he said.
But he added: "The problem here surely is not the attack doggery of the press but that politicians of both main political parties have allowed this to happen."
Solutions to the problems that led to the inquiry were then discussed, including:
:: Offering those who are written about in newspapers an automatic right of reply;
:: Creating a Parliamentary definition of the public interest;
:: Establishing a regulator that would examine what had happened when things went wrong and work out how to stop it happening again;
:: Making it easier for journalists to be whistleblowers on their industry by developing an avenue for them to air their concerns about what they are being asked to do.
Lord Justice Leveson questioned how all this would be financed, however, and also signalled that he was not in favour of a system of licensing for the press.
"It's critical we get a system that everyone can live with that meets the requirements of our democratic society but also meets the legitimate complaints that have bubbled up more than once in the last 20 years and now have to be dealt with," he said.
Prof Petley was joined by Professor Ian Hargreaves of Cardiff University's School of Journalism and Dr Daithi Mac Sithigh of the University of East Anglia.
Prime Minister David Cameron set up the Leveson Inquiry in July in response to disclosures that the News of the World commissioned Mulcaire to hack murdered schoolgirl Milly Dowler's phone after she disappeared in 2002.
The first part of the inquiry, sitting at the Royal Courts of Justice in London, is looking at the culture, practices and ethics of the press in general and is due to produce a report by next September.
The second part, examining the extent of unlawful activities by journalists, will not begin until detectives have completed their investigation into alleged phone hacking and corrupt payments to police, and any prosecutions have been concluded.
PA
