I'm no expert, but I wouldn't take it as given at all that the Irish constitution doesn't protect bond holders against that. It's interesting that the UK SSR has an objective of trying not to interfere with people's property rights. That's exactly the area where similar legislation could come into conflict with our constitution. But, having said that, there's no law (even constitutional law) that can't be changed. Though, as Goosebump points out, it's one thing having a provision like this on the lawbook, another thing entirely actually using it.The legislation contains a range of measures to safeguard deposits, no matter if senior bondholders were led to believe (either in debenture provisions or previous legislation) they'd be treated parri passu with depositors. Naturally, there are safeguards and compensation measures to prevent bondholders being ripped off (e.g. if bank assets are transferred to a 'bridge bank').
Unless you think Irish constitutional law imposes some other protection of bondholders, the existence of the SRR in the UK suggests that EU law and the common law are no barrier to the state insisting depositors are protected more strongly than bondholders, in spite of private contract and pre-existing statute law providing for equal treatment.
In any case, as someone wondered earlier, how much senior debt is actually left outstanding? I don't pretend to understand the details but if it's the case that most senior debt has already been rolled over and converted into debt that we owe to the ECB, what difference does it make?
If it's the case that the debt has been rolled over, but is simply guaranteed by the state, ie. the creditors haven't actually been repaid in cash, then maybe we have more room to maneuver.
I wonder if all of this is what Colm McCarthy cryptically referred to as "broken field rugby" last night?