Agile Tools put up a great post about the degrading relationships on a team when manager/leaders don't trust the team. Estimates are sandbagged, scope is padded, deadlines are moved around, all sorts of games are played to compensate.
Wouldn't it be much simpler to work on the trust issues and move forward. I agree with the author that mistrust is as much your problem as it is theirs. Someone has to extend trust first to build a good relationship.
If you want to be entertained, then click through to the post and read my short play (in the comments) describing my interaction with a Product Owner who had ridiculous ideas about how to game the system rather than overcome the trust and commitment issues.