Johnson believes it is imperative the club move to a bigger stadium if they are to move to the next level.
He told the club's official website: "This is D-Day for the club. We're trying to build something long-term here, something for the future and a new stadium is vital for those plans. We have everything else in place - the team's doing well, the chairman is backing us and we have new training facilities but the one major piece of the puzzle, our home, doesn't fit.
"There are financial considerations but also ones that affect us every day. The new stadium can bring in new fans, give us better facilities, help attract top new players and much more besides."
Meanwhile, City have reported record losses of £6.56million for the year ending May 31 2009.