Arsenal manager Arsene Wenger feels the Gunners have a big financial edge over Tottenham Hotspur, but admits that will change once the Lilywhites move into their new stadium.
The north London rivals were on even financial footing prior to Arsenal's move to the 60,432 capacity Emirates Stadium in 2006, but the Gunners have in recent years stretched ahead of Spurs financially after paying off the their debts resulting from the costly construction process.
Tottenham have begun work on a 61,000-seater stadium as part of the Northumberland Development Project, though, and hope to move into their new ground in time for the start of the 2018/19 season.
"It is the biggest challenge we face," said Wenger, ahead of the north London derby at the Emirates on Sunday. "It will be purely down to the technical quality of work.
"On a financial level, we always had level power because when we had 37,000, 38,000 seats [at Highbury] we were level.
"After we moved into the new stadium we had less financial resources than them because we had to pay our debts back. That was always the case.
"Now, maybe in the last two or three years we are in a stronger financial situation, but that will not last because they build a new stadium as well."