Possible Clues:

• 'Mean as custard' for 'keen as mustard', say
• Fighting a liar, e.g
• Reverend's mistake: lovey-dovey type is married
• A slip of the tongue? — no promises (anag)
• Burly chassis for Shirley Bassey, say?
• Something said by self-described birdwatcher?
• No promises to be broken? It sounds the wrong way round
• Promises no changes -- an error in speech
• Unintended exchange of early letters with old golf club by wretched miser
• "Let me sew you to your sheet," e.g