arm's-length relationship in British English
(ˈɑːmzˌlɛŋkθ rɪˈleɪʃənˌʃɪp)
nouna relationship lacking intimacy or friendliness, esp when possessing some special connection, such as previous closeness
the healthy arm's-length relationship between government and broadcasting
Public bodies must maintain full arm's-length relationships with private companies.