English to French Marketing International Org/Dev/Coop Manual

It is a manual about awarding grants and sub grants.
Many time this expression is used: chief of party.
If I translate as "chef de partie" this can mislead, as a "chef de partie" is a chef in catering.
If I translate as "responsable de parti", this makes think of "parti politique" and it is not the case.
I am looking for suggestions.

Here is a sentence where the expression is used: "If the subaward amount falls within the delegated signature authority of the chief of party, the country office staff with responsibility for grants management and administration will normally be responsible for negotiating with subawardees."