Do not get involved. Try to minimise your own additional work due to that colleague. In one-to-one meeting with manager, let the manager know. Use the words: I just wanted to bring your attention to one more matter. Then describe the challenges that you face. Not your team. Do not gang up, do not conspire or collaborate. Do not mention about how other colleagues feel the same way. If your manager takes a negative opinion of these activity, you'll be fucked, because such a thing would create a negative impression. If the manager is not inclined to go by your judgement of your colleague's competence, you'll lose face. But it's much easier to control the narrative and restore your manager's confidence in you in a one-on-one conversation, than when it's a group mutiny. No matter what others tell you, do not get encouraged. People often sound like they're with you, but they often are not. They won't back their statements, and you'll be alone holding the bag. And moreover, if you stay out of it, you'll be able to carry the high ground of being above the fray, out of politics, and being balanced. Don't do netagiri of this sort. Conserve it for initiatives for which getting consensus is harder. It might be possible that you're the only one feeling so strongly about it. Then you may be in need of a weekend, or someone to vent to, or even therapy. But get your hate in check.
