The ardfheis defeated a motion to decriminalise cannabis for personal use.A Galway motion noted that the current law was "criminalising huge numbers of young people who otherwise would never have come before the courts".
The motion was defeated by 82 votes to 63.
Mr Danny Callanan, a Galway-based solicitor, argued that cannabis was "a calming drug" which did not lead to the social ills caused by alcohol.
