I'd like to see that happen. I don't think you can.
You can be a government relations firm and not do lobbying in the sense that you can do a lot of public affairs activities, one of them not being lobbying, which means you can do stakeholder management, advocacy, etc. But just given the rules, I think any interactivity with government you'd want to register, so therefore you would become a lobbying firm, just to be on the safe side.