The latest Echo Research survey findings, revealed exclusively at the conference and reported in PRWeek last week, showed how negative press coverage has tarnished PR's image during the past two years.
'Scumbags', 'insensitive', 'manipulative charlatans', 'sleazy' and 'disingenuous' are just some of the descriptives slung at the industry by the British press, Echo chief executive Sandra Macleod informed the audience.
The dark art of political and monarchical 'spin' - the undoing of Jo Moore, Sophie Wessex et al - had spread like a cancer across the PR spectrum, upsetting journalists and dragging the industry to damaging new depths, according to the research.
Although most PR work is based on honest and open dialogue, the industry is having its own PR nightmare, with falling morale among some of its practitioners.
'I am fearful that the professional industry I work in is going to be classed along with estate agency,' ZPR director Zaria Pinchbeck told the panel.
Too late, according to panelist Amanda Platell, the New Statesman columnist and former Conservative Party director of communications. 'I have heard friends class PR with estate agents. The industry has been discredited by spin and needs a hearty overhaul,' she said.
The consensus was that the industry must seek to win back its credibility by divorcing itself from spin-doctoring, which has blurred the boundaries between true PR and propaganda.
BBC political correspondent Nicholas Jones, who has written extensively on New Labour's obsession with news management, hinted at a tighter code of conduct for the political PR arena, where spin is damaging the democratic process and undermining political journalism's credibility.
'There is a danger of encouraging other PR sectors, such as financial PR, to mimic the Government's malpractices,' said Jones.
The off-camera, off-the-record world is making journalists push their stories further than the facts allow, 'even to the point of making it up, safe in the knowledge that no-one will be any wiser,' he said.
But it was felt that enforced regulation may do more harm than good to a sector that relies on creativity and flexibility to be competitive.
At the very least, televised political briefings, based on the US model, should be adopted, argued Jones.
But there does exist an old-fashioned, self-imposed model of ethics - a method championed, ironically, by the media representatives who had come to help remedy PR's recent ills.
'Just be honest with journalists. Tell the truth. Vendettas will be carried out against you if you have lied to us and we'll get our own back.
Seriously, we will. We resent being misled,' said Kirstie Hamilton, the outgoing City editor of The Sunday Times, who is entering the PR world next month when she joins Tulchan Communications.
'Always try and put up a CEO for comment,' she urged the delegates.
Sky News business editor Michael Wilson advised PROs to stick to using the phone. 'Call us. E-mails and long press releases will get you nowhere. PR shouldn't cheapen events. Know what we do and give us the story straight,' he said.
Ministry of Defence director-general of corporate communications Martin Howard said that even if a PRO's motive is considered honourable, he or she 'should never, ever lie'.
'I am always honest with journalists and never seek to mislead by deception,' he said.
'You can only lie for so long but you will get caught. Then the relationship with that journalist or media organisation will be damaged forever,' added Platell.
Dow Jones Newswires EMEA senior editor Gabriella Stern said PR is inexorably linked to corporate strategy and IR and PR departments must co-operate for effective communications.
'Don't bury the news,' she said.
One delegate dismissed the call for more honesty, and claimed the New Labour spin-machine was a product of a hostile, ruthless and often dishonest 24-hour news industry: 'All Peter Mandelson and Alastair Campbell have done is adapt to the demands of the media,' he argued.
Clifford agreed, but added that there are cases when lying becomes necessary in the context of a PRO's work: 'I would much rather tell the truth but an important part of my job is lying and deceipt because with fewer and fewer honest journalists around, and the way they put their own spin on stories, you treat them as they treat you.'
This method seems to work for Clifford: 'I've never pitched and I've never had a contract. Last year I turned over £1.5m,' he declared.