"This would lead to the licence fee being seen as another form of general taxation. The trust will not sit quietly by and watch this happen," he added.
Lord Carter, author of the Digital Britain report, said that a proposed merger between BBC Worldwide - the corporation's commercial arm - and Channel 4 would not be "a forced marriage", but that the government "would be ready to facilitate it".
Referring to a consultation, he said the government would not be "running a referendum on it" but would take the views of licence fee payers into account.
Channel 4's chief executive Andy Duncan welcomed the report, saying it "offers crystal clear acknowledgement of Channel 4's vital role in ensuring public service competition to the BBC".
Digital radio is at the heart of the proposals
He added talks towards a merger with BBC Worldwide had made "considerable progress".
Lord Carter's Digital Britain report also says that all national radio stations are set to be upgraded to digital by 2015.
The date of the upgrade - on which stations will cease broadcasting on FM - will be announced two years in advance.
The government has outlined plans to work with vehicle manufacturers to provide digital receivers, and radio sets which cost £20 or less.
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