Second-level teachers said yesterday their industrial action was an "action of last resort" and they would rather be in their classrooms teaching pupils.
The president of the Association of Secondary Teachers, Ireland (ASTI), Mr Don McCluskey, said teachers were reasonable people who were unhappy taking such widespread industrial action, but had no choice.
He called on the Government to make a last-minute intervention and open up "meaningful discussions" with the union.
"Disputes are settled by talk. It's the only way," he said.
At their last press conference before today's strike Mr McClus key and the general secretary, Mr Charlie Lennon, issued details of a survey which claims 64 per cent of adults support paying teachers more.
The survey by Behaviour and Attitudes Ltd interviewed 1,200 adults.
The question asked was: do you think secondary school teachers should be paid more? Respondents were not asked their views on whether 30 per cent was justified.
In April The Irish Times published a poll which found 46 per cent of the public favoured paying the ASTI 30 per cent; 45 per cent were against; with the rest undecided.
The survey, conducted between October 23rd and 31st, also found 77 per cent in favour of paying teachers for extra-curricular activities.
When asked to rate the quality of the education in their school 43 per cent of respondents said "fairly high quality", 37 per cent said "very high quality" and 10 per cent said "poor quality".
"The results of this survey clearly indicate that the work teachers do is highly regarded by the public, and the majority see merit of our case for a substantial increase in pay," Mr McCluskey said.
However, Mr Lennon said it was inevitable that there would be some erosion of the union's position with the public as the industrial action "begins to bite in schools".
He said there would remain a "solid groundswell" of support among the public who might be annoyed at the industrial action but would basically support it.
As the ASTI prepared for its strike day, the largest teacher union, the Irish National Teachers' Organisation, emphasised it was taking a different course of action.
It said the Government should state clearly that the way to deal with the ASTI claim was through the new benchmarking review contained in the national pay deal.
Its general secretary, Senator Joe O'Toole, said: "We are confident that progress can be made by staying within the partnership process and through bench marking."
Mr George O'Callaghan, general secretary of the Joint Managerial Body, which represents most school managers, said he hoped the two sides would come together "sooner rather than later" to resolve the dispute.
Mr Michael Moriarty, general secretary of the Irish Vocational Education Association, which represents most vocational schools, said that unless the sides talked schools would be going into "a long dark tunnel" for the next few months.