@ NL1001 : Why don't you go back to your bank manager/mortgage broker and negotiate a few things?
Firstly, €1500 per month interest on a €355k mortgage equates to 5% interest. There's no way you should have to pay that much interest in your position. The average variable rate at the minute is 3.5%. Even AIB have a 2 year fixed rate of 3%. By switching to a variable, you'd save yourself the guts of €500 per month on interest. That's not to mention the your TRS rate.
Secondly, you can get a 10 year Interest Only mortgage on investment properties. Switch to this, and you'll be saving the €500 per month on your capital payment every month (no point in paying off the capital when the value's falling!).
By doing these two things, you'd be saving €1000 per month on the €2000 per month you're currently paying.
Then, if you take in €600 per month in rent after management fees, all of a sudden the house is standing you €400 per month, again exluding whatever TRS you're entitled to.
So surely you'd be able to move back to the UK, live rent free, pay the €400 per month to keep your Irish house ticking over, and save for your deposit over there?
You're in a great position to bargain with the bank. They don't want to take your house, as they don't want the hassle of trying to sell it and chasing you for the difference.
This way, they still make their interest, you keep the house, you move to the UK for a better standard of living, and you can save for a place of your own.
Everyone's a winner!