Bonds are fixed in most cases for ten years, some are longer and shorter, if the e.c.b buys (political) all the bonds and creates a euro bond, happy days interest payments are 100 basis points, 2 billion, (soverenty gone). At the present time the e.c.b is mandated to buy 40% 80 billion so leaving about 120 billion in the private sector with an average yield of 425 basis points (4.25%).
Without the e.c.b the interest would be 9 billion average not including for risk purposes.
Now if your in the private sector and your bonds are maturing, would you repurchase at yields of 100 basis points, no way, you would want at least the same yield your getting as the e.c.b cannot purchase any more bonds.
Now if your the e.c.b with 80 billion of Irish bonds trying to offload to the private sector at 100 basis points, I would say good luck trying to get bids, (they will have to raise rates to get bids) they can repurchase but at some point they will offload the bonds at higher yields creating greater risks increasing higher premiums and so on.
Can the country afford these payments, if it can then my point has no credibility, if it cannot then pay the debt over time less the interest portion and stop borrowing and start saving nominal sums for the decline in the economic cycle