Up to a quarter of a million young people are locked out of their schools today as ASTI members in 500 secondary schools have downed tools in a row over a series of issues, including equal pay.
At least 6 more strike days are in the pipeline, and it's also unclear whether hundreds of schools will be able to re-open after next week's mid-term break, because of problems with supervision and substitution.
Michael McGrath is on the executive of the ASTI and he teaches at St Augustins in Dungarvan.
There are 18 elected regional reps and in his role he represents 32 schools in his region.
He explains to Beat News why members are united on strike action:
"90% of the teachers out on strike today have nothing to gain personally, no personal gain, no monetary gain, we don't want a wage increase, we've taken the pay cuts and we're all down a lot since the actual financial emergencies.
And the FEMPI legislation, they brought in the USC cuts and there's pension levies, and I've about ten negatives on my salary for deductions on my pay because of FEMPI.
I don't want those removed - sometime, but not today - today is about the newly qualified, the lesser paid teachers is the proper word for them who have up to five years teaching, with masters degrees, with everything.
And a simple analogy, the take home pay for a newly qualified teacher is as low as less than €400 per week - I'm not joking you. I could produce those payslips from people who are taking home less than €400 a week. They have an honours degree, a masters degree, six years in college.
That is so, so unjust and unfair.
In a nutshell, we want to be able to sit in our staff rooms and with clear conscience look at our colleagues and say I have done my duty towards you, I want you on the same pay scale I am."
Further talks will take place tomorrow following today's strike action.