Manchester United have lodged a complaint with the Football Association regarding their ticket allocation for the third round FA Cup clash.
City host their crosstown rivals at Etihad Stadium on January 8 but the Red Devils are not happy with the 5,500 tickets they have been offered.
FA rules order the home club to offer 15 per cent of the capacity to the visitors, which in this case would come to 7,100, and United want their full privilege.
The FA have now been called in to mediate the situation with City claiming the aforementioned amount of away fans would constitute a safety risk.
