The Government parties moved closer last night to establishing an agreed approach, which would seek to change the present multiseat proportional representation electoral system.
The Progressive Democrats have for the first time come out in support of calls by the Minister for the Environment, Mr Dempsey, for an examination of alternatives electoral systems.
During the summer Mr Dempsey suggested a new electoral system based on single-seat constituencies elected by a combination of proportional representation and a list system.
A PD spokesman said last night the party was "seeking a serious commitment" to examine the subject in the review of the progra mme for government to be concluded by the end of the month.
The party's General Council will publish a paper on its preferences for reform in October.
The Constitution determines that TDs "shall be elected by the system of proportional representation by means of the single transferable vote"'. It also forbids the enactment of any legislation "whereby the number of members to be returned for any constituency shall be less than three".
Any change to the system would require a constitutional referendum. In 1959 and 1968 Fianna Fail sought unsuccessfully to replace the present system.
The PDs policy document is also expected to address the issue of the number of Dail deputies.
The number of TDs is determined by law although the Constitution specifies that the total number shall not be fixed at less than one member for each 30,000 of the population or at more than one member for each 20,000 of the population.
While any alteration to the system would require a referendum the number of TDs could be reduced from 166 through legislation. By applying the 30,000 people per TD level ail constituencies the number of TDs would automatically come down to below 120.
Fine Gael and Labour have already give negative responses to suggestions of electoral reform. However, the subject takes on greater significance with the PDs backing an apparent Fianna Fail wish to change the system.