Enterprise Inns has denied alliegations that it has made legal threats against the Parliamentary Committee probing pubcos, as well as the media.
The claims were made by MP Greg Mulholland, who told Parliament last week: "I need to bring to the attention of the House a separate, very important and worrying matter. Enterprise Inns is Britain's most notorious pubco.
"Its reputation is shown by its incredible litigiousness. It has tried to sue local media and national media, and has indeed threatened honourable Members of this House.
"I do not know if you are aware of this, but Enterprise Inns has sought by way of legal threat and intimidation to prevent the Business and Enterprise Committee from carrying out its scrutiny of the activities of the pub company."
But a spokesman for Enterprise flatly denied the accusations.
"Yet again, the allegations made by Mr Mulholland are not true. It speaks volumes that he only makes such comments under parliamentary privilege."
However, Mulholland has hit back, saying: "It's very unfortunate that Enterprise Inns has put out a bland and rather meaningless comment and they are not prepared to say specifically what they are claiming to be untrue; that speaks volumes."
Enterprise has declined to make any further comment.
At the Committee hearing last Tuesday, chairman Peter Luff MP said he had been "bitterly disappointed" by the reaction of certain pubcos to the summer's report.
He said: "I am not used to being unable to comment on my own reports for fear of litigation."