Speaking in an interview with Swiss-French newspaper Le Dimanche, Lennart Johansson said the recent Moscow theatre siege and crowd trouble between Greek and Turkish fans in a recent UEFA Cup match, would have an impact on the decision.
But Johansson stopped short of suggesting the bids from Russia and a joint one from Greece and Turkey were doomed to failure.
He also suggested internal disputes in Ireland over the use of stadiums there would be taken into consideration.
Said Johansson: "The UEFA Cup crowd trouble a the terrible hostage drama in Moscow. That will also be taken into consideration for the final decision, as well as what has happened in Ireland. We have to bear all that in mind."
If the negative impact of the events steer UEFA away from handed their tournament to those countries, it elevates the Austrian-Swiss joint bid, and that from the Nordic countries of Sweden, Finland, Norway and Denmark into pole position.
Although Johansson denied the two bids were favourites.
He told the paper: "If you say that, you know more than I do,"
Seven bids are being considered by UEFA (Russia and Hungary and joint bids from Ireland-Scotland, Greece-Turkey, Bosnia-Croatia, Austria-Switzerland and the Nordic nations) with a final decision due on December 12.
Two bids to host UEFA's Euro 2008 tournament have emerged as favourites after the president of European soccer's governing body seemed to pour doubts on a number of the other bids.
