Update 4.00pm: The Department of Foreign Affairs has apologised for the delay in issuing some passports, saying it is due to staff shortages and extra checks on certain applications.
So far this year, over 100,000 passport applications have been processed with over 90% completed within 10 working days.
DFA General Secretary Niall Burgess said it can disheartening dealing with delays.
"It is a matter of immense frustration for use that some categories of passport application are taken longer to process then we had planned."
"That we are unable to answer all phones calls to the passport office and that many are concerned that they will not receive their passports in time to make their travel plans."
Update 12.00pm: LIVE: Department of Foreign Affairs 'unaware' of anyone who missed a flight due to passport delays
The Department of Foreign Affairs says it's not aware of anyone who has missed their flight due to delays at the passport office.
However, Deputy Catherine Murphy of the Social Democrats says she has heard of one person who missed a family wedding because their application was not processed on time.
22,000 applications have taken up to eight weeks to be processed - with some of the blame being placed on first-time applications and stolen passports.
But speaking at the Public Accounts Committee, Secretary General of the DFA Niall Burgess, has said he has not heard of anyone missing a flight.
He said: "Nobody who is caught up with these delays, who submitted a passport with one expectation in terms of the processing time and then found that their application, nobody who came to our attention, that we're aware of, has missed a flight.
"If you lost your passport and you discover it on the morning you're due to travel, you'll miss your flight."
Earlier: The office in charge of issuing passports will be questioned by TDs today about why it is taking people so long to get one.
Checking first time renewals and lost passports are just some of the reasons for delays at the passport office according to those in charge.
The Public Accounts Committee wants an explanation for the delays - with reports some people are waiting up to eight weeks to get their passport.
The committee's chair has called the situation a "mess" that has caused "unnecessary upset and trauma" for families going on holidays.
Pat Dawson, CEO of the Irish Travel Agents Association, cannot understand why it is taking the office so long to process applications.
He said: It really is beside me why the department hasn't got ahead of itself.
"Knowing that there was a big increase in people getting Irish passports and there should be well and truly bells ringing two or three months ago as opposed to now."
- Digital Desk