What is the relationship between Volker Kauder and chief whip in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

Underlining the stakes involved, the party's chief whip Volker Kauder this month vowed to impose sanctions on any dissidents in his ranks -- a threat that may have backfired by antagonising backbenchers.

Answer: position_held