The Government will publish legislation today that will pave the way for the abolition of 80 town councils, merge six county councils into three, and reduce the number of councillors in the State from 1,650 to 950.
The Local Government Bill will involve the biggest change in the organisation of local, city and county politics since the laws that established most of the current set-up in 1898.
It is expected to come into effect ahead of the local elections next summer, where the two councils in each of Tipperary, Limerick and Waterford will also be merged into one.
The Bill was approved by Cabinet at its meeting ahead of the budget on Tuesday.
Fine Gael Ministers had pressed for an earlier publication, but Labour had argued that more scrutiny was required of the Bill, which runs to 65 sections and will involve wholesale changes for local authorities across the State.
In the event, the only substantive amendment has been a new power of veto given to councillors on the appointment of chief executives of councils.
The county manager position is being abolished and the balance of power between elected councillors and full-time officials has been shifted in favour of the councillors.
The provision to abolish town councils has been strongly opposed at local level. But Minister for the Environment Phil Hogan has argued the current set-up is anomalous with some big towns which have grown in the past 100 years having no town council, and others that have seen population decline retaining theirs.