Former Health Minister James Reilly says the ability of the current Minister to overrule a recommendation to not pay for a ground-breaking Cystic Fibroses drug is 'a dangerous place to be'.
The state's medicines watchdog - the National Centre for Pharmacoeconomics - believes 'Orkambi' is too expensive.
Senator Reilly previously overruled a recommendation from the NCPE in relation to another drug from the same company Vertex.
However in that instance he says the cost was reduced and the drug worked in 'an absolute fashion', while Orkambi only works in a percentage of those treated.
Health Minister Simon Harris has written to his colleagues abroad, calling for a joint approach to try and get the drug at a more affordable price.
Senator Reilly says its a difficult situation: "I think it’s a dangerous place to be, because you are going to be accused of playing God basically.
"And you are going to be making decisions around drugs that can be the difference between longevity and a very short life in some instances."