Bém countered by calling Gazdík "self-important."

Last fall, the two mayors agreed to switch jobs for a week, in order for each to get a better understanding of the other's position. Bém was to run a village of 1,080 inhabitants, and Gazdík a city of more than 1 million.

However the agreement was put off until mid-August, due to Bém's knee operation, and the angry Gazdík said that he could expect a "shower of rotten eggs" when he does arrive in Sucha Loz at best.

Bém, in an open letter to Gazdík, reprimanded him for his efforts to turn the issue into a media campaign.

"At the time we made the agreement, I asked you not to medialize the plan. I was convinced that you did not suggest this project for the sake of popularity, but in order that we both could come to understand the responsibilities, worries and even joys of the other. …What happened happened and now I am surprised to hear things about liars, cowards and carpet bombing by rotten eggs by the Association of Friends of Pavel Bém," Prague's mayor wrote, adding that the agreement still stands.

"I assure you that when you come to Prague, you will be in no danger of flying rotten eggs, fruit, vegetables or worse. You will receive a hearty welcome and I hope that your experience at the head of the Prague City Hall will help you grow personally and professionally," he concluded.

The exchange is to take place in the third week in August.