Ad agency boss accuses Cardownie of "poisonous" smears in Twitter rant Scotland's top ad man has sparked a spectacular bust-up with the city's deputy leader by accusing him of spreading "poison" about his firm's flagship campaign for Edinburgh. Gerry Farrell, who personally created Irn-Bru's most iconic television campaigns, accused Steve Cardownie of sabotaging his firm's disastrous "Incredinburgh" Winter Festival campaign. The Leith Agency boss launched an astonishing tirade on Twitter following the public backlash against the city council marketing drive - dubbed "absolutely appalling" by some critics. In a series of ill-tempered messages seen by thousands of users on the site, he dubbed veteran politician Cardownie "King Cobra" and suggested he had leaked details of the campaign in advance of its launch - which Councillor Cardownie flatly denied. The attack came shortly after Cllr Cardownie's appearance on Reporting Scotland ahead of the Winter Festival launch on Sunday. He wrote: "Phew! Another read: "We've all heard of outsiders p*****g in, but insiders p*****g in, that's really sad. Leaker-in-chief Steve Carbattery. When contacted by the Evening News, Mr Farrell insisted the views were personal and did not represent his firm. But in a statement he later added that he would meet us with Cllr Cardownie "one-to-one, face-to-face, any time, any place, any pub" to discuss the matter. Insiders at the council are said to have been left speechless at the outburst and privately suggested it would count against Mr Farrell and his business in the future. The Leith Agency is known for its Irn-Bru commercials and has been hired to front the Scottish Government's flagship health campaigns. It is not known how much Marketing Edinburgh - which is owned by the city council - paid the firm, but the major drive had a budget in the region of £300,000. Mr Farrell yesterday appeared to spark at least one other argument with a marketing executive from another firm, and went on to described critics as "turd-slingers." Cllr Cardownie, the city's festivals champion, said: "It seems totally unprofessional to sink that low and make personal comments. I have never made any personal comment about Gerry. I've only met him once or twice. Obviously the criticism about the campaign has touched a nerve and he doesn't know how to handle it, but I don't think it will do him or his agency much good that he has degenerated into this kind of language. Cllr Cardownie said that The Leith Agency had "a great reputation" but that there has been concerns about the winter campaign on this occasion. He added: "I've never made any criticism at this chap himself, it's just the campaign. I have actually commended him and his agency. But it's lamentable this guy thinks this is the way to go about things. He might come to regret this as it does him and his agency a disservice. In response, Mr Farrell insisted he had not referred "directly" to Cllr Cardownie. Mr Farrell said: "Any views I express on Twitter are my personal ones and I defend my work. I have never referred directly to Steve Cardownie in my recent tweets. People can draw what inferences they like, that's up to them. I defend my work against anyone that throws mud at it and I would generally invite any critics to come into the agency. I'd be very happy to take the opportunity to discuss our work face to face. I've never had this opportunity with Mr Cardownie but I'd welcome that. A lot of the people in the council have been very supportive of the campaign. We were asked to change one word of the campaign, Incredinburgh, which we did. "It is regrettable that the word "Incredinburgh" was anonymously leaked to the media just two weeks before the official launch in what appeared to be a vindictive spoiling tactic. The word was designed as a hashtag to "magnetise" all social comment surrounding the campaign on social media. As such, it would have been the very last word an audience would see.