shoulder to shoulder
US /ˈʃoʊl.dər tə ˈʃoʊl.dər/
UK /ˈʃoʊl.dər tə ˈʃoʊl.dər/

1.
standing or working very close together, often in a supportive or united way
:
•
The protesters marched shoulder to shoulder down the street.
•
We stood shoulder to shoulder against the injustice.