Informal studies have observed that Google tends to prioritize original reporting over re-reported content.

If your boss insists that you take on the project, go over your project or task list and ask him/her to re-prioritize, explaining that there's only so much you can take on at one time.

At the start of the iteration, the product owner can re-prioritize the release backlog so the development team knows the items it needs to work on next.