Fianna Fáil MEP Billy Kelleher said he raised the issue of relaxing Covid-19 rules governing their return to Ireland from Belgium or France before the controversy over the Oireachtas Golf Society Event in Clifden last month.
Speaking on RTÉ's Today with Claire Byrne, Mr Kelleher said he has since written another letter highlighting the challenges faced by MEPs.
He said: "We can fly to Brussels and go about our parliamentary business, but when we fly back we have to self-isolate for 14 days."
Mr Kelleher said while some work can be carried out remotely, MEPs cannot participate in plenary sessions if they are not physically in parliament, which would be the same as saying TDs cannot go to the Dáil.
In a joint letter to the Government, Fianna Fáil, Fine Gael and Green Party MEPs asked that the 14-day quarantine requirement be lifted for MEPs who receive a negative coronavirus test before leaving Brussels.
They argue that the requirement restricts their ability to carry out their duties when moving between Ireland, Brussels and Strasbourg, the seat of the European Parliament.
The request follows the resignation last week of Phil Hogan, Ireland's EU Commissioner, after it was found he had not followed the obligation to restrict his movements when arriving from a non-Green List country.
Mr Kelleher said if the current regulations to remain in place he would "effectively be in self-isolation for 56 days between now and Christmas" if he was to participate in plenary sessions in the European Parliament.
He said:"We are not asking for anything to be done beyond what is the case for other essential workers, like HGV drivers, pilots and jockeys."
He also acknowledged that he broke quarantine rules when he attended the election of the Taoiseach in the Dáil earlier this year.
"I apologised, it was wrong and insensitive. I was led to believe like other MEPs in Europe, that if you are testing you are exempt from self-isolation."
Speaking on the same programme, Fine Gael MEP Seán Kelly said they were not looking for special treatment, but seeking clarity as they have been told Covid-19 restrictions could be in place for as long as two years.
This is the letter sent to an Taoiseach @MichealMartinTD. To be clear, we are seeking clarity and guidance for the purpose of fulfilling our duties as MEPs, and of course will fully comply with any guidance Government provides pic.twitter.com/rKmkCcBF40
— Seán Kelly MEP (@SeanKellyMEP) September 4, 2020
"We want to abide fully by the rules.
"Now that the summer is over we will be making legislative changes. Discussing amendments is almost impossible to do via teleconferencing. If you are not present in parliamentary debates, you cannot participate," he said.
