Leo Varadkar (Dublin West, Fine Gael) | Oireachtas source

The scheme was introduced in 1994 by the then Minister, former Deputy Michael Woods, and was a very progressive measure at the time. I imagine when it was introduced that the decision not to make it retrospective was due to the enormous cost that would arise from doing so. Using €290 million from the social protection budget in any given year would be very difficult. A consequent decision would have to be made, for example, not to increase pensions at all for a year in order to allow for reform of that scale. I am not sure how well that would be received, if at all. The distributional effect would tend to benefit better-off retired couples rather than the least well-off retired couples, if it were to be done. How we calculate the contributory State pension, which has a number of anomalies as it stands, is something that we will have to consider as part of the overall reform.

See this speech in context