It's the Canada Revenue Agency that would be delivering the proposed grocery rebate, and it would be doing so through the GST credit system. That's the system where the CRA is delivering the benefit four times a year to a large swath of the population. Currently, you have about 11 million individuals and families who are receiving the GST credit. Essentially, in terms of changes to their information technology systems, it's certainly easier to build on something that's already functional and to make the necessary changes rather than to start from scratch.
That also answers the second part of your question, I think, sir, about efficiency and the limiting of administrative costs as well.