"A council has asked staff not to smile when dealing with parking complaints - as it may make drivers angrier.
Staff on induction training for the parking complaints team at Brighton and Hove Council were told a smile could make a row worse.
A spokeswoman at the Tory authority said: "The training is designed to help staff use body language that would not inflame the situation."
But Mark Turner, of the GMB union, scoffed: "I find this astounding. They should focus on useful training that employees really need."