"The alternative is to keep these facilities closed until we reach herd immunity and we can't say when that is."
The Government is set to "examine" the possibility of applying the same "vaccine exception" to cinemas and other activities as indoor dining.
When asked if there was a possibility that other indoor activities that recently reopened such as cinemas, hair salons, and non-essential retail would also employ the system, Taoiseach Micheál Martin didn't rule out the option, adding that they will "work with the sectors".
"We will examine now the advice as we've received in respect of that from the National Public Health Emergency Team (NPHET)," he said.
"We have to work through it."
Leo Varadkar added that the Government only planned to use the green cert for international travel and not domestic services, saying that the new advice is "a big and difficult change".
"The alternative is to keep these facilities closed until we reach herd immunity and we can't say when that is. So this might just be the right way forward," he said.
Varadkar added that the new advice is "not undoable", however, it does have "consequences" and could be "decisive".
The recommendation would see many young people excluded from indoor activities over the coming months as people in their 20s are not set to receive both Covid-19 jabs until September.
