A Labour MP who has declared his candidacy for the party's leadership today called on the government to block media tycoons from owning more than one national newspaper.
John McDonnell said the move was necessary to safeguard the dissemination of "reliable" information.
Mr McDonnell, the MP for Hayes and Harlington outlined the plan as part of a series of media reforms he said were missing from the government's schedule, which was outlined by the Queen at the state opening of parliament today.
He put regulation of the media at the heart of his agenda, arguing that the public was being denied a wide range of information because of the "unacceptable levels of concentration of ownership".
The MP - who chairs the National Union of Journalists' parliamentary group - said the government should have powers to force media owners to relinquish some of their titles, diluting the ownership structure in the UK media.
"The UK media is controlled by a decreasing number of wealthy individuals", Mr McDonnell said. "This bill will ensure the media is regulated by the state and the public in order to provide quality and reliable information to the public."
However, his proposals are likely to receive short shrift from politicians and Rupert Murdoch, the media proprietor most likely to be hit by his plans.
Under Mr McDonnell's proposals, staff and reader representatives would have a place on the editorial boards of all national newspapers.
He published his plans as part of his "alternative Queens speech", with the document covering policies he believes should be in place under a future Labour government.