The Green Party is to distribute a leaflet to 130,000 homes in the Dublin region calling for a referendum to decide on Ireland's membership of the NATO-led Partnership for Peace.
The Government has already decided against a referendum as its legal advice is that membership is fully in accordance with the State's policy of "military neutrality". A motion outlining the terms and conditions of PfP membership is expected to be submitted to the Dail early next month.
In its leaflet the Green Party claims PfP membership would involve Irish troops in joint exercises with NATO forces - possibly on Irish territory; a major increase in Ireland's defence budget; an undermining of Ireland's neutrality and a boost for the arms trade.
Discussions between NATO and officials from the Department of Foreign Affairs are understood to be near completion, after which the Government is likely to publish a "presentation document" setting out the relations between Ireland and PfP.
Green Party TD Mr John Gormley said: "According to a recent MRBI opinion poll, a majority of Irish people want a referendum on PfP. The Government is refusing to give this basic democratic right."
PfP was established in 1994 to provide a framework for regional security co-operation in Europe.
The PfP structure allows member-states to sign up for different levels of involvement.
The Government's document is likely to commit Ireland to involvement in humanitarian activities.