Attempts to create as few as eight councils in Wales can go ahead but only after elections to the country’s assembly next May.
This followed a deal between the Labour administration and Plaid Cymru, which had previously voted with the Conservatives and Liberal Democrats to block the Local Government (Wales) Bill.
Plaid Cymru said it had secured agreement from Labour that no reorganisation of Wales’ 22 councils would happen until the new assembly was in place.
Public services minister Leighton Andrews, who has issued plans for forcible mergers to create only eight councils said afterwards: “Let no-one in local government now doubt that reform is coming and reorganisation will happen.”
Plaid Cymru leader Leanne Wood said if her party gained power it would seek reform “retaining the existing 22 local authorities [but] making them work together as combined regional authorities”.
She added: “Plaid Cymru has also ensured that we will have the ability to introduce proportional representation for local councils to allow for fairer voting systems like the single transferable vote.”
The Wales Local Government Association criticised the continued uncertainty for councils and their workforces.
A spokesperson said: “Continued speculation around local government reorganisation is making life intensely difficult for local councils who are trying to plan and reform local services in the face of major financial pressures.
“It also impacts on the morale of hundreds of thousands of local government workers who are being adversely affected by the insecurity such on-going speculation causes.”