This catch phrase is frequently used as a real negotiation tactic. It is deadly to serial negotiations, but in the right situation, it can be effective. Before this is used, take a measure of the offeree to reduce the risk.
Negotiator 1: “Will you give me a bit of leeway to do everything I can to make this engagement successful?” Negotiator 2: “Sure, I want success.” This gives Negotiator 1 a long leash. Generally, the further up the management scale you get, the more the ends outweigh the means.
To stop this behavior, let your adversary get away with it once, provide notice of consequences, and let the hammer fall should it happen again. This tactic can turn the best negotiations to mush, so you must shut it down vigorously at some point if the risk outweighs the benefit.