(CNN) - John McCain’s chief media adviser said Tuesday he is stepping down rather than campaign against Barack Obama.
Mark McKinnon said last year that he would leave McCain’s campaign after the primary season if the Arizona senator were to run against Obama.
The Illinois senator is not the Democratic nominee, but he has accumulated a significant lead in the number of delegates required to claim the nomination.
In a 2007 interview with Cox News, McKinnon said he would vote for McCain, but "I just don't want to work against an Obama candidacy." He added that if Obama were to reach the White House, it "would send a great message to the country and the world."
The McCain campaign says McKinnon will remain a “major supporter” of the McCain’s presidential bid.