Fine Gael leader Simon Harris has said that he "does not agree" with the remarks made by Ryanair CEO Michael O'Leary.
Mr O'Leary spoke at an event on Saturday night to endorse Peter Burke, Fine Gael's Longford-Westmeath candidate.
Mr O'Leary said: "The Dáil is full of teachers. Nothing wrong with teachers, I love teachers but I wouldn't generally employ a lot of teachers to go out and get things done."
Teachers' unions the ASTI, TUI and INTO all condemned the remarks.
ASTI General Secretary Kieran Christie branded the comments as "ignorant and risible" and "baseless jibes", adding that they were "compounded by a cheap and sycophantic reaction by Fine Gael activists".
Mr Harris described teachers as "the backbone of Irish society", adding he was not sure there are many people who would survive five minutes at the top of a classroom.
He said Mr O'Leary was one of the country's most successful businessmen, and it was notable that he thought Mr Burke was doing a good job at the Department of Enterprise.
Mr Harris said that while the Dáil did need diversity, Michael Noonan and Enda Kenny, who "helped get the country out of the economic mess my party inherited, were teachers".
He said teachers were doing "a very good job".
Sinn Féin leader Mary Lou McDonald called on Mr Harris to clarify Mr O'Leary's remarks.
Speaking at a Save Moore Street rally in Dublin, Ms McDonald said that "teachers get the job done everyday in the classroom for our children.
"I think it is completely inappropriate that they would be jeered and demeaned in the way that they were at a Fine Gael event. It is hard enough to get teachers into our classrooms.
"I think Simon Harris as the leader of Fine Gael needs to come out and clarify this matter," she added.
Mr Burke said: "I agree with him [O'Leary] on some issues, I disagree with him on other issues. We live in a democracy which allows for disagreements and debate."
He said that as a "father of a five-year-old and eight-year-old, I deeply value the work our teachers and educators do in shaping our children's futures.
"I'm proud of their contribution and am doing all I can to increase resourcing to support their work for the betterment of our communities."
Meanwhile, Fianna Fáil leader Micheál Martin said he 100% disagrees with Mr O'Leary's comments.
He said the primary education system has been a significant part of the formation of modern Ireland.
Labour Party Ivana Bacik also said it is very disappointing to hear anyone taking "snipes or sneers" at teachers, particularly at a time when there is a recruitment and retention crisis in education.
Speaking in Dublin as the party unveiled its 32 General Election candidates, Ms Bacik also called on Government parties to distance themselves from Mr O'Leary's comments.
She said: "Everyone of us are meeting people all the time, parents of young adults who qualified as teachers and who simply cannot afford to live in a home close to where they teach.
"We meet principals and other teachers who are distraught because they simply cannot recruit the number of teachers needed to staff the schools. [There are] 951 vacancies currently across primary and special education."
Social Democrats Jennifer Whitmore said Mr O'Leary had disparaged every teacher in the country while endorsing a party in government for 14 years.
Additional reporting Marc O'Driscoll
