To work at arm's length

to work disadvantageously.

See also: Arm

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
Perhaps most importantly, it required whoever the lead partner was on an audit to rotate off that project every five years, reducing the tendency of those who are supposed to work at arm's length from getting too cosy.