An employer cannot penalise, or threaten an employee with penalisation for proposing to take parent’s leave or for taking parent’s leave
Penalisation includes:

(a) dismissal, or threat of dismissal 
(b) unfair treatment including selection for redundancy or unfavorable change to terms and conditions

If you feel you’ve been penalised for taking parent’s leave and it has led to your dismissal, you can make a complaint to the Workplace Relations Commission
under the Unfair Dismissal Act (1977)