The Fianna Fáil leader has said the lack of clarity on the Leaving Cert is unacceptable.
The government has said the plan is for the exams to go ahead at the end of July.
However, there are growing calls for the exams to be scrapped and replaced with predictive grading.
Fianna Fáil leader Micheál Martin says there needs to be clarity soon and that the failure to address the issue is "remarkable."
He says every government in Europe has been "confronted with how to complete school-leaving exams and prepare for a new higher education year" and that nowhere has there been such a "lack of clarity and confusion" as in Ireland.
An online petition calling for the Leaving Cert to be cancelled has been signed by over 26,000 people.
The current plan is to hold the exams at the end of July, but there are a number of health concerns, including social distancing.
Teachers' unions met last night to discuss the various issues and are expected to hold more talks today.
Fianna Fail’s education spokesperson, Thomas Byrne, thinks it will be called off.
He says: "It's certainly looking like that. As an opposition TD, we have been completely locked out of the Department of Education on this one. So they are not keeping us informed.
"I have to say that is unlike every other Department. All of my colleagues from the Taoiseach's Department, from the Health Department, are involving opposition TDs in briefings.
Uncertainty continues on whether this year’s Leaving Cert exams will go ahead as expected in July as alternative assessments are officially brought to the table.
Wednesday went by without a decision made on contingency plans for the Leaving Cert as students, parents, teaching unions, principals, school patrons and other educational bodies met with the Department of Education.