BYELECTIONS ARE “an entirely unsuitable method of filling casual vacancies” at parliamentary level here, a leading academic in politics has said.

Prof Richard Sinnott, of the school of politics and international relations at UCD, was yesterday addressing the Oireachtas Joint Committee on the Constitution.

In his address on the effects of the current PR single-transferable vote (PR-STV) system on the proportionality between votes and seats, he said minority parties and governing parties were at a significant disadvantage in byelections in the Irish context.

When assessing the suitability of byelections in the PR-STV system, he said one must remember that in a byelection there was usually just one seat to fill in a multi-seat constituency. The quota a candidate must reach to be elected was 50 per cent of the poll, plus one.

“This raises the bar or threshold of election very substantially compared to what was in the constituency in question in the preceding general election.”

This would generally deprive a small or minority party, which had held the seat, of the seat in a byelection situation.

A governing party candidate would also find reaching the very high threshold difficult “given the tendency for voters in second order elections to vote against the government”.

“In short, because of differences in the size of quota, the pattern of representation that results from byelection is highly likely to differ substantially from the pattern that resulted from the original general election. This distortion makes byelections an entirely unsuitable method of filling casual vacancies occurring in systems of PR.”

He said in other PR systems, general list systems of PR were used to fill casual vacancies “by simply taking the next name on the list of the party whose member has created the vacancy” to replace the representative.

A further criticism in the Irish context he said was that the system led to an “excessive constituency orientation of TDs”, and he agreed it was true TDs did a “great deal of constituency work”.

There were causes for the high attention given to constituency work other than the electoral system, however, including “fundamental features of Irish political culture, the small size of Irish society . . . problems in the administrative system and the weakness of local government”.