Your question stated"deliberately misleading councillors" and by all rules for professional conduct make the answer to that a resounding NO. Misleading, is a form of lying of course and even just taking the Nolan principles into account doing so contravenes almost all of them.
As stated, becoming a councillor and fighting incorrect actions or decisions previously made is what the democratic system is designed to facilitate. Just using innuendo and gossip as a basis of challenge is not the way forward but, producing evidence and drawing support for your cause and securing victory, is.