Number of tiers
Ireland
Answer
1
Source
Constitution of Ireland 1999-05-27 (last amended: 2012-06-27) :http://www.taoiseach.gov.ie/eng/Historical_Information/About_the_Constitution,_Flag,_Anthem_Harp/Constitution_of_Ireland_August_2012.pdf
Comment
Article 16
5° The members shall be elected on the system of proportional representation by means of the single transferable vote.
