Talk to them early now. I still distrust about the consultants. Understand there may be other reasons for desire to outsource (personal connection, returning favour, step towards more work with consultants in future.) Make your offer not just something that will make you look great and will also make your manager look great and their life easier. Here's an idea: offer to be the point man for interfacing with the consultants. Do you take charge of the interaction, get on their side as well, and then when all things go sideways, step in yourself and clean up the mess. After all, by that time you'll be the only one who knows how to fix it.