The Minister for Social Protection has confirmed that the Public Services Card is now mandatory in order to access services from her department.
Regina Doherty claimed the card is not compulsory as "nobody is required by law" to have one.
She confirmed however that government departments will refuse to provide citizens with the basic public services they are entitled to if they refuse to sign up.
"Nobody will drag you kicking and screaming," she said.
"This is mandatory to access public services originally now from the Department of Social Protection - but I understand there are other departments that are going to make it mandatory."
Minister Doherty was speaking on Newstalk Breakfast after it was revealed that a woman in her 70s was refused her state pension because she did not want to sign up for the card.
She said the legislation introducing the card was passed in 2005 - adding that her department has made it compulsory in recent years so that staff can verify people's identities.
Previously, passports were used to verify identities.
She said Department of Social Protection services amount to over €20bn per year:
"We believe [...] that it is not too much to ask people to authenticate who you are so that we can give you a fast and efficient public service to make sure you get what you are entitled to," she said.
National Identity Card
The Irish Council for Civil Liberties has written to the government outlining its concerns over the card - and called on the Minister for Finance Paschal Donohoe to clarify whether the cards are mandatory.
The group is one of a number of organisations to express concern that the government is attempting to introduce a "national identity card by stealth" without any public debate or scrutiny.
The cards were originally made mandatory for social welfare recipients and pensioners seeking free travel.
They have recently been made a mandatory requirement for anyone wishing to sit the driver theory test and will soon be required to apply for a passport or driving licence.
Minister Donohoe has previously insisted that it “is not and will not be” mandatory to have a PSC card.
The Public Services Card is capable of containing detailed biological data including facial recognition, fingerprints and eye scans.
The contract to provide the cards was awarded to a private company, Biometric Card Services. The state will reportedly receive a discount on that deal if 3 million identity cards are issued by the end of this year.
Approximately 2.75 million have been issued to date.
National identity cards are compulsory in a number of European countries - where citizens can be arrested for failing to produce them.
Civil liberties groups have warned that the compulsory requirement to carry them has the potential to be "used a tool of petty harassment" by law enforcement.