Senior officials in the Department of the Marine and Natural Resources drew up a plan for the Taoiseach's Department two months ago which involves devolving key functions to one or more agencies.
The plan, which has been seen by The Irish Times, envisages shedding most of the responsibilities of the Department, but does not recommend abolishing it altogether.
Overall responsibility for policy and EU negotiations would be retained, but the separate agency or directorates would handle coastal property and management, seafood regulation and enforcement, capital infrastructure programmes and corporate services - and would charge for functions where possible.
Since last week's decision by the Taoiseach to amalgamate Communications and Natural Resources into one new department, there has been sustained criticism from the marine sector.
The Taoiseach, and the new Minister, Mr Dermot Ahern, have both denied that there was any attempt to "downgrade" the marine department, with the Taoiseach stating that the length of the title was the main factor. However, he also stated that a junior minister with responsibility for marine would be appointed.
Speaking in Luxembourg earlier this week, Mr Ahern expressed confidence that "marine" would be restored to the title, and said that the Taoiseach was not averse to the idea. The plan prepared by senior civil servants within the old Department of the Marine and Natural Resources suggests the change is more fundamental, and signals a shift in policy.
It says that a "coastal property management and development directorate" would handle foreshore leases, dumping at sea permits, foreshore estate management, fishery harbours and iceplants. A "seafood regulation and enforcement directorate" would handle aquaculture licensing, sea fisheries licensing and management, and seafood enforcement and control.
A spokesman for the Department of Communications and Natural Resources said he understood the proposal had not yet been submitted to the Taoiseach's Department. Restructuring of the department was a Government decision, and had no connection with civil service proposals, he said.