You have to find it. You can't necessarily immediately grab it, for instance, out of the extended health insurance from which public sector employees currently benefit. Eventually, that will become a savings both to those employees and their employers, but in the short run, to incentivize the program you need to find a revenue tool to bring money into the system.
One of the things you have heard from private sector employers at this committee is that they are willing to embrace a model of pharmacare. There have been surveys of employers in Canada in recent years that show a surprising number of Canadian employers would be willing to contribute in some way to a publicly run plan, because the public plan is better capable of managing the costs. One of those things means they won't pay for just anything at any price, because no rational country in the world does that. The only actors doing that, unfortunately, are Canada's private insurers, and it is costing us dearly as a result.