I would like to discuss a task similar to “The next step falls between responsibilities.”

A possible distinction: A decision that others depend on has not been made.

Possible first output: A short decision brief covering options, consequences, missing information and actions following approval.

I would like to check whether this first step fits our task and discuss terms for further work.

Our situation: [add details]
What we want to change: [add details]
What we have tried: [add details]