The Government should lead cross-party talks on monopoly media ownership, according to deputy Labour leader Harriet Harman.
Harman said the issue of media ownership needed to be tackled as it was a feature of the Leveson inquiry that has not yet been dealt with.
But Culture Secretary Maria Miller did not commit to any talks, pointing out that Lord Justice Leveson said the inquiry did not have time to deal with the issue in detail.
Miller said the Government would be "seeking views" on the issue in the summer rather than having more political discussion.
Turning to Miller during culture questions in the Commons, Harman said: "There is the important issue of monopoly media ownership left to deal with.
"In fact, of course, monopoly ownership prevents the market operating by preventing new entrants to the market as well as being bad for democracy.
"Can I ask you to do what the Government did before and actually set up and lead cross-party talks on the question of media ownership?
"Because I am sure the Lib Dems, and certainly we, would be very willing to work to support a deal with this part of the Leveson inquiry which is important and has not yet been tackled."
Ms Miller replied: "I think we already have an agreed way forward on this which is that we are going to be seeking views on these issues in the summer.
"As Lord Justice Leveson himself said, he wasn't able to devote sufficient time to look at the media plurality matters in detail and I think that's what we need to do now.
"So rather than having further political discussion I think what we need to do is seek the views on these issues to be able to provide the sort of broad policy framework that we need in this area."
Earlier this month, Harman, who is also shadow culture secretary, called for a 15 per cent cap on media ownership as well as the introduction of a "fit and proper person test" for proprietors.