Manchester United have defended their ticket pricing policy for this weekend's FA Cup tie against Fulham after the London club complained about it to the FA.
Fulham filed the complaint after finding that some United supporters were able to purchase seats equivalent to those on offer to visiting fans for £5 less.
Announcing it on their Twitter feed, the club said: "Fulham Football Club has contacted the FA to complain about Man United discounting FA Cup match tickets for their fans.''
The two clubs had agreed - as is FA Cup practice - a standard price of £45 for home and away tickets, but United members were able to purchase theirs at a discounted price of £40.
The Old Trafford club said the members-only offer should not have come as a surprise to Fulham. But the Londoners maintain that they were not told about it and would not have agreed to the price disparity if they had been informed.
"Fulham fans are paying the same as United fans who are not members," a United spokesman said. "A discount scheme has existed for members for around 20 years. We're surprised it has come as a surprise to them.''
The spokesman said the members' discount scheme was also in operation for the 1-0 replay win over West Ham in the previous round.
The FA is understood to have written to United to ask for a formal explanation.
Information from the Press Association was used in this report