Depending on what your company is doing (or you are doing for them in the UK), they may have Corporate Tax liabilities in the UK as well as Ireland.
They are probably hiding their heads in the sand about this, and that is not a sensible thing to do.
As you are likely to be resident in the UK, you are legally responsible for declaring your income there (whether or not the tax man finds out). You should also be paying UK Social Security. It is very likely that you will be found out at some point.
However, your employer also has a legal responsibility to operate UK PAYE and NIC on your salary, and this could cause problems for them.
The UK Government are losing out on your Tax and NIC, and they will pursue this if they find out. Although you are paying full and fair tax in Ireland, the UK Government don't care about that - they want you to pay your tax there. In Ireland, as I stated above, if you have a liability, you get credit for UK tax paid - not the other way around.
The last case I had of this, was in the opposite direction - worker in Ireland being paid by UK company they operated UK PAYE and were refusing to operate Irish PAYE which they were obliged to do- he eventually got his company to agree to sort the position out, although I believe it took a lot of persuasion on his part.