What do you mean by "the pension"?
Contributory (PRSI linked) or non-contributory (means tested)?
https://www.citizensinformation.ie/en/social-welfare/social-welfare-payments/older-and-retired-people/state-pension-contributory/
The State Pension (Non-Contributory), previously called the Old Age Non-Contributory Pension, is a means-tested payment for people in Ireland aged 66 and over.
www.citizensinformation.ie
What is the status of the tax and PRSI arrears and what, if anything, have Revenue and the Department of Social Protection respectively said to you about them and dealing with them?