Thanks for answering, Roger, by Tories I meant Conservative party of Britian. In Britian, Conservative party is often call as Tories. It's sarcasm in a sense that a guy, to whom saying this, is a fan of this party, and I want to tell him that he can get a "job" in/at/with that party if he quits his current job!
Since now you know the context and what I meant by Torries, I hope now you can answer my question more surely. I guess it has to be either "at" or "with", no?