The IPA's Direct Marketing Charter, which outlines what it believes is DM best practice, aims to encourage the most professional use of direct among its members.
In 2002, the IPA approached the DMA, proposing they join forces as part of its "big tent" initiative. However, the DMA rejected the proposal.
Agencies, however, still felt their needs required IPA attention. Chris Thomas, the chief executive of Proximity London, said: "Agencies need an authoritative group that can draw together varied streams of thinking in the industry to ensure a degree of consensus on key issues."
The IPA's Charter covers similar issues to the DMA's agency council, with some crucial policy differences, and the move is expected to bolster the number of agencies paying for IPA membership. Some agencies felt the DMA, which has a broad membership of advertisers, suppliers and agencies, was not best placed to represent agency concerns.
James Kelly, the managing director of the DMA, said: "There is crossover with what we do, but we welcome it. We look forward to working with the IPA."