Hi Irishguy
Assuming your pension plan is an "occupational pension scheme", under the preservation requirements of the Pensions Act, you are entitled to your employer contributions upon leaving service once you have 2 years "qualifying service".
Qualifying service is defined as period of service as a contributory member in the relevant scheme plus the period of pension service of any scheme that you have transferred into the relevant (current) scheme.
The terms of your current pension plan may be more generous than this (check the booklet) but this would be relatively unusual.
If your plan is a PRSA, you will be entitled to your employer contributions irrespective of your lenght of service.