The Department of Social Protection has said checks carried out by its officials at airports and ports have a "firm legal basis" and are "vital" to combating fraud and protecting taxpayers' money.
The department said it would address issues with the Data Protection Commissioner directly, after the watchdog earlier expressed doubts about the legality of certain checks.
In a statement to RTÉ News, the department said it undertakes control checks at airports and ports.
"These checks have a firm legal basis under Section 250 (16) of the Social Welfare Consolidation Act 2005, as amended."
It said: "These checks are vital in order to combat social welfare fraud and protect taxpayers' money.
"The Department of Social Protection is in ongoing engagement with the Data Protection Commission in relation to this matter.
"As there are a number of legal and technical matters involved, the department will be addressing these matters directly with the Data Protection Commission."
The Dáil's Business Committee was to discuss a request for time to be set aside in the Dáil to put questions to Minister for Social Protection Heather Humphreys, following a statement from the Data Protection Commission which raises doubts about whether welfare inspectors acted lawfully at airports.
Social Democrats TD Gary Gannon wrote to the committee as well as to Ceann Comhairle Seán Ó Fearghaíl saying this is a matter of "utmost concern and one that deserves to be dealt with in the Dáil immediately".
The Dublin Central TD said it is imperative that the Dáil sets aside time today, before it breaks for the summer recess, so that the minister can answer questions on the DPC statement.
Meanwhile, Sinn Féin is seeking a special sitting of the Dáil next week to discuss what it says are serious concerns around checks by welfare officials at airports.
RTÉ News understands that the party's spokesperson on Enterprise, Trade and Employment, Louise O'Reilly, has this evening written to the Ceann Comhairle seeking a Dáil debate on the issue.
She said the issue cannot be allowed to "slide off the agenda" because the Dáil is due to go in to summer recess tonight.
It follows a statement from the Data Protection Commissioner (DPC) in which it raised "serious doubts" about whether social welfare inspectors were acting lawfully when gathering information at ports and airports in relation to the Pandemic Unemployment Payment (PUP).
The DPC has asked the Department of Social Protection to provide information about what basis their inspectors had stopped and questioned people at airports, including asking them for personal information and their PPS numbers.
In a statement, the DPC said the department had confirmed that in respect of certain flights over the last number of months, all customers boarding the flights were and continue to be asked their details.
Ms O'Reilly said: "The DPC has cast serious doubt about whether social welfare inspectors were acting lawfully when collecting and processing passenger data at ports and airports in relation to Pandemic Unemployment Payment payments."
The Deputy Data Protection Commissioner, Graham Doyle, stated that: "The DPC cannot see how this practice of collecting information from all passengers simply on the basis they are travelling to a certain destination conforms with the powers of inspectors under the 2005 Act to act and question (and therefore collect data from) a passenger where they have reasonable grounds to believe there has been a contravention."
Louise O'Reilly said: "This brings into question the judgement of the minister, or ministers, who instructed these inspectors to carry out these data checks for the purpose of suspending the welfare payments of travelling passengers.
"There are many questions which need to be answered about this situation and it cannot be let slide off the agenda due to the Dáil recess.
"Given the serious nature of this matter and the doubts cast on the legality of the action by the DPC, I think it is imperative that the An Tánaiste and Minister for Enterprise, Trade, and Employment, Leo Varadkar, and the Minister for Social Protection, Heather Humphreys, come into a special sitting of the Dáil next week to answer questions on this murky and possibly illegal situation."
The legal rights group, FLAC, has said it is very concerned by the DPC's statement which it says has deepened its concerns around the activities of the Department of Social Protection.
FLAC Chief Executive Eilis Barry said: "It is now incumbent on the Minister to instigate a review into the activities of Social Welfare Inspectors at airports and to ensure that Departmental policy properly reflects the limited powers that are available to agents of the Department at ports and airports."