Sacha Deshmukh, chief executive of MHP, claims the documentary, aired last night, may end the Tories’ honeymoon period and change public perception of the new Government.
The show, named ‘Tabloids, Tories and Telephone Hacking’, also centred on targets including News International, the Metropolitan Police and the Press Complaints Commission.
It comes as the Conservatives enter the second day of their annual conference in Birmingham.
The programme alleged Andy Coulson, now Tory director of communications, asked to hear intercepted voicemail recordings of celebrities and other public figures while News of the World editor.
Deshmukh said: ‘I think this marks the first big move out of the honeymoon period for the Tories, with a change in terms of their public perception.
‘I think Coulson may consider his formal position but still continue to influence policy from the sidelines.’
Steven Barnett, professor of communications at the University of Westminster, said: ‘The programme raises a very profound question about Parliament’s ability to regulate phone hacking and other unethical practices by journalists.
‘In particular, it raises doubts about whether the interests of Rupert Murdoch’s News International are being placed above the public interest.
‘The suggestion that our MPs are being intimidated by powerful press interests, and that a thorough police investigation may have been compromised by the same press interests, ought to raise alarm bells for anyone concerned about illegal and unethical behaviour by certain journalists.
It is imperative that these allegations are thoroughly investigated, and that MPs are prepared to stand up for the public interest.’
The programme follows months of pressure on Coulson, who resigned as NoW editor in January 2007 after royal correspondent Clive Goodman was jailed for four months for phone hacking.