But frustratingly the powers that be don't care about chimps as much as they should. Your only hope is to convince them that chimp-using research is nearly useless to humans, so that even their undersized compassion for chimps will convince them to shut the research down.

The problem is that these kinds of lies create a viscous cycle. Someone who shares your utility function and honestly believes your lies will want to shut down research even in cases you wouldn't and will feel justified inventing lies (on top of the lies he believes to be true) to promote that position. Then people start believing those lies and so feel justified inventing further lies, etc.