Despite the proposal receiving applause in the hall, when it came to a show of hands, the move was comprehensively rejected.

Trinity College Dublin Young Fine Gael proposed legalising the use of cannabis for “personal consumption, sale and production” on the grounds that it would take users out of the reach of dealers, expose “the so-called war on drugs” as having failed, and because no long-term link to mental illness and the banned substance had been proved.

Justice Minister Alan Shatter strongly opposed liberalisation of the drug laws, insisting that campaigners were wrong to claim that smoking cannabis did not lead to long-term health problems.

Mr Shatter used the debate at the Fine Gael ard fheis to hit out at a “nameless” TD, believed to be legalise cannabis campaigner and Roscommon TD Luke ‘Ming’ Flanagan, over his “devotion” to the drug.

The minister said that worrying links between prolonged cannabis use and mental health problems such as schizophrenia had been proven.

The legalisation move was rejected on a show of hands, though around 10% of delegates backed the liberalisation bid.

But the minister did not get his own way when it came to a motion calling for the Garda vetting system to be replaced. It was passed by delegates despite Mr Shatter’s opposition to the move.

Mr Shatter told the ard fheis that children would be put at risk by extending the validation of clearance from one to two years.

A move to bring in much tighter controls for the cash-for-gold industry was backed by the ard fheis.

A motion calling for Ireland to begin accession talks with Nato was also voted down by delegates.