Two of its backers, Express Newspapers and Independent News & Media, have refused to contribute extra funds for new activity proposed above and beyond its basic remit.
While the two newspaper groups remain members of the NMA, they have left rival newspaper groups to press on with funding for a new programme of events without them. This has caused resentment among some of the other members.
The extra financial commitment was proposed in a recent presentation by the NMA's chief executive, Maureen Duffy, and Richard Webb, the general manager of News Group Newspapers, who is also the chairman of the NMA board. Although Express and Independent remain committed to their initial investment levels, sources said they had still failed to pay for this new wave of marketing activity.
Duffy denied that the two companies had refused to pay up: "We have no problem with them. They have both undertaken to give a particular amount of money because we put forward ideas for other projects and activities."
Lawrie Procter, the commercial director at Independent, said: "We agreed to an NMA budget for three years and if additional funding were required we'd consider it on a project-by-project basis. We haven't fallen out with the NMA or any of our partners - it only works if everybody is together."
A spokesman for Express Newspapers said: "Express Newspapers continues to be part of the NMA."
The NMA's work has included research projects on male and female reading habits. Sceptics said when it launched that it would struggle to control rival papers.