If Valentina Matvienko leaves St. Petersburg to join the Council of Federation and Kozak heads the northern capital, he will need to increase the rating of United Russia in the city, where the party lost influence because of the declining confidence of townspeople in current governor. According to experts, in such a situation restoring the position of United Russia in short terms can only be successful if done by a St. Petersburg native with a positive public opinion who served in federal government in Moscow and is familiar with the city. Kozak is likely to head the list of the party in elections to the Duma.

Meanwhile, the Kremlin made no comments as to the possible appointment of Deputy Prime Minister governor. A Presidential Administration insider said that "there is no direct connection" between the fact that Kozak "will head the list of United Russia "and him possibly becoming governor. Another source in the Kremlin administration said that it was Deputy Prime Minister who was charged with conducting a check of the results of Valentina Matvienko’s government in St. Petersburg, since he previously worked in Smolny under the leadership of her predecessors Vladimir Yakovlev and Anatoly Sobchak.

According to The Russian Mafia web-site (rumafia.com), Kozak studied at the Law Faculty of St. Petersburg University at the same time with President Medvedev. In Smolny he worked with Prime Minister Putin, under the leadership of Anatoly Sobchak. In 1991 he was head of Law Administration of the City Council. Since 1994 he headed Law Committee in City Hall, and also served with Putin in the city government.