united front

When disparate groups or individuals band together to work on a project or achieve a goal together. For example, several non-profits may present a united front to support or oppose legislation that would affect the people they serve, even though they may otherwise compete for contracts against one another.

The term was originally based on its military applications in terms of different forces allying against common enemies, and also used in terms of revolution and reform movements against common foes.

Although they often disagreed about parenting methods, Bob and Jane decided they would have to have a united front when dealing with Billy's Internet addiction.