Army and politics? I don't think Gallia would allow that. Officers who're engaged in politics (too much) are dangerous for the Royal Family.
Politics and army? Unlikely. You could create activists group in civilian fighters using....Unione Course ID/Gallic Junkers ID, perhaps. And only the request Gallic fighters. If your reasoning is fine, I'm sure they'll let you use them without problems. GRN ID doesn't suit political groups.
I also don't like your numbers... 25% of Gallic population? That's really, reeeeeeeally much! I think the Council support should be around 40%, but the Council is alternative House, let's say.