David Cameron, Ed Miliband and Nick Clegg are expected to meet again to discuss the Leveson press reforms after they held "good" talks.
The party leaders held 45 minutes of discussions on proposals for a new system underpinned by a Royal Charter.
A Labour source said: "It was a good meeting, but there are still issues to be resolved.
"The discussions will continue. The party leaders expect to meet again in the next few days."
The meeting came after Labour moved to ensure it will have the option of adding tough statute-backed reform into the Crime and Courts Bill next week.
Responding to pressure from the Opposition, Lib Dem home office minister Jeremy Browne gave assurances that there would be an opportunity to debate "Leveson-related amendments" on Monday.
The development means unless Mr Cameron makes progress on the issue he is likely to face a Commons vote - which he could lose as Labour and the Lib Dems join forces with some Tory backbenchers.
The progress of the Defamation Bill has already been halted after peers led by Lord Puttnam inserted a new clause which would set up a statutory oversight body for press regulation.
Lord Skidelsky has also tabled similar amendments to the Enterprise and Regulatory Reform Bill.
Sources played down the idea that the parties were on the verge of hammering out a deal.