Campaigners are set to make an ass out of local politicians by putting up a donkey as a candidate for mayor.Marko - whose standing for office in Varna, Bulgaria - is promising hard work, no kickbacks and a mulish determination.Society for a New Bulgaria campaign director Angel Dyankov explained: "Unlike the other mayoral candidates and politicians, Marko has a strong character, doesn't steal, doesn't lie, and gets the work done."Incumbent mayor Kiril Yordanov has refused to share a platform with his rival saying it is "undignified".But Mr Dyankov commented: "He is right. Just think how Marko would feel sharing a stage with such a political crook."It would be very undignified for any self respecting donkey."