Why do you want to leave your current job?
Stay positive regardless of the circumstances. Never refer to a major problem with management and never speak ill of supervisors, co-workers or the organization. If you do, you will be the one looking bad.
Sample Answer
I am really looking for a new challenge at an innovative company.
In my discussions with manager I get the impression that you are really looking to create a foundation for your {program} I also get the impression that you are willing to try out new technologies and methods like {name technologies or methods}.
While {My Current Company} does promote innovation, I think that {Your Company} really takes it seriously and that’s the type of firm that I want to partner with.