Planning permission has been granted for 2,300 homes on the site of the former Phoenix Park racecourse, despite strong opposition to the development.
An Bord Pleánala granted permission, having rejected an appeal against the proposal by the Phoenix Park Preservation Association.
In its decision, An Bord Pleanála said it the development was in accordance with the "proper planning and sustainable development of the area".
However, opponents of the development claim there is insufficient infrastructure to support the scheme and the 75,000 residents in the Blanchardstown and Castleknock area are already struggling with the present infrastructure.
Labour's Dublin West TD, Ms Joan Burton said the development was a "textbook example of everything that's wrong" with the planning process.
"It is a landmark site and should have been used for amenity and greenfield purposes, preferably associated with racing.
She said that four new towns have been built in the Dublin 15 area in the last five years and there was poor infrastructure in terms of public transport and schools for residents already in the area.
"The people who buy these apartments and houses will pay on average #100,000 to €150,000 to €200,000 for the sites alone, leaving aside the building costs.
"It will all go to the speculators that brought this about.
"However, I accept An Bord Pleanala have made their decision and we'll have to live with that," she added.
Since the racecourse closed in 1990 there have been a number of controversial development proposals associated with the site, including the building of a Casino.