Possible Clues:

• An eavesdropping device in church? If absolutely necessary
• If necessary when an arrest is made
• Chain apt to break under pressure
• A simple sporting chance given to church if absolutely necessary
• Seems the nipper has just about got there
• A simple putt given to companion if absolutely necessary
• A bang on the chin worked, if all else failed
• One to get money from measure in case of necessity
• If really necessary
• Just about