A group of academics specialising in privacy and data protection law have said they are “not aware” of any legal requirement for people in receipt of social welfare payments to register for the public services card (PSC).

Eleven experts have written to Minister for Justice Charlie Flanagan expressing concern about the Government’s card project after it emerged that a woman in her 70s had her State pension cut off because she refused to register for a card.

She has not been paid her pension for 18 months because she refused to go through the registration and identity-verification process as requested by the Department of Social Protection. As a result she is owed about €13,000.

The woman said she felt “bullied” following several letters from the department inviting her to register. No one had been able to demonstrate that the card was “mandatory”, she added.

In a letter sent on Friday, the academics noted what they said was “the intent to turn the PSC, which was originally intended to be used for specified public service purposes only, into a general purpose identity card to be used in a wide variety of contexts under the Social Welfare and Pensions Bill 2017”.

“It would appear that the time has now come where a national identity card is essentially on the table, and it is time for policy decisions in relation to this matter,” they wrote.

They said that to date, there had been “no public engagement in relation to the development of policy for a national identity card”.

“Our concern is that as a result, we are sleepwalking into developing a national identity index and national identity card in all else but name, and that we have not considered the very important implications before doing so.”

They called on the minister to “engage with the public for the development of policy on this matter, and for there to be a real debate on the issue”.

They asked that the minister recommend that further expansion of the card be delayed and that the provision in the recent Social Welfare and Pensions Bill extending its use not be enacted until the matter had been aired and policy considered in depth.

The group also noted that in 2015, then minister for social protection Joan Burton said the question of introducing a national identity card had not been part of the remit for the so-called SAFE scheme to register welfare recipients.

Ms Burton said in the Dáil that such a measure would require “due consideration by the appropriate agencies before any policy decisions could be formulated by Government and would require the development and implementation of legislation to support any such policy”.

The academics said it was “now being made effectively compulsory to have the PSC in order to carry on ordinary business in our society (for example to get a driving licence or a passport)”.

They noted the Department of Social Protection was now writing to social welfare recipients stating that registration for the card was “now a legal requirement for people in receipt of social welfare payments (including Child Benefit) or free travel entitlements”.

“We are not aware of any such legal requirement,” they said.

The group includes Dr Stephen Farrell of Trinity College Dublin, Dr Alan Greene of Durham Law School, Prof Steve Hedley of UCC, Dr Rónán Kennedy of NUI Galway, Prof Maeve McDonagh of UCC, Dr TJ McIntyre of UCD, Dr Maria Helen Murphy of Maynooth University, Dr Patrick O’Callaghan of UCC, Dr Darius Whelan of UCC and Prof Robert Clark, UCD emeritus professor, who wrote the first Irish book on data protection.

The Data Protection Commissioner said it had “strongly conveyed” its views on the public services card project on numerous occasions to the Department of Social Protection that there was “a pressing need for updated, clearer and more detailed information to be communicated to the public and services users regarding the mandatory use of the PPSN and PSC for the provision of public services”.

Fianna Fáil Seanad spokeswoman on social protection Catherine Ardagh said it was “essential” that both houses of the Oireachtas were provided with an opportunity to debate and consider the possible human rights and/or data protection implications of introducing such a system of national ID cards.

“Any measure or initiative designed to effectively establish a State database of citizens’ information requires a comprehensive debate, and the fact that a public services card will soon be required for all passport applications, driving licences and driver theory tests means that this debate needs to happen once the Oireachtas returns,” Ms Ardagh said.

The card was introduced to replace the old social welfare card and some other cards used for State services and about 2.75 million have been issued to date.

The Department of Social Protection has a target of 3 million cards to reach by the end of this year.

It said on Friday the card did not have any of the typical characteristics of a national identity card in that people were not required by law to register for one and it was not compulsory or mandatory for individuals to hold or carry one.

It said An Garda Síochána was specifically precluded from requesting an individual to produce a PSC as proof of identity.

“The public services card is exactly that – a card is designed for the purpose of safely, securely and efficiently providing public services.”