The Minister for the Environment, Mr Dempsey, is finalising plans to establish a Greater Dublin Authority to take charge of strategic planning, including land use and transportation.
The authority's remit would extend to Meath, Kildare and Wicklow, with powers to regulate all public transport services as well as infrastructural development, including major road and rail projects.
The Cabinet sub-committee on infrastructure has been considering setting it up since last spring. But the key additional element would involve extending its remit to include strategic planning.
This radical departure from existing local government structures has been prompted by disquiet among Ministers about large-scale "freelance" land rezoning, particularly in the outer counties, in defiance of the Greater Dublin Area Strategic Planning Guidelines.
Though the guidelines - which became statutory on January 1st - were intended as an overall framework for the region's development, recent decisions by councillors in Meath, Kildare and Wicklow have called their effectiveness into question.
These decisions, mostly taken against planning advice, include proposals for major housing schemes, business parks and shopping facilities in areas never previously considered for development, such as Kilbride in Co Meath and Newtownmountkennedy, Co Wicklow.
Mr Dempsey's Department has written to Meath and Wicklow councils, asking them to explain how some of their latest plans for large-scale housing and other developments in non-designated areas comply with the strategic guidelines.
The first annual review of the guidelines last April stressed the need to implement a strategy consolidating the metropolitan area and linking new development closely with rail-based transport. "This is the only way forward," it said.
Commenting on the move to set up a strategic land use and transportation authority, the Dublin city manager, Mr John Fitzgerald, said the stage had now been reached "where the pressures on the planning system require a new approach".
He emphasised that the authority would deal exclusively with strategic issues, such as fixing the routes of new transport links and the location of developments with an impact that transcended the boundaries of the seven local authorities in the region.
The Cabinet sub-committee on infrastructure, chaired by the Taoiseach, is understood to have decided that the new authority would take over and extend the Dublin Transportation Office's functions.