Arsenal boss Arsene Wenger has hit out at Manchester City's limitless cash resources. City, owned by Sheikh Mansour, and Paris St Germain have been criticised for massive sponsorship deals with companies enjoying close links to their billionaire backers.
Etihad Airways have a 10-year agreement with City bringing in close to £400million a year, with many believing they have deliberately paid above the market price to pump money into the club.
Arsenal boss Wenger, whose side visit City tomorrow, said: "If the sponsorship deals are just a way of getting round financial fair play then it's not financial fair play.
"It makes the system worse for me, as that would mean it makes a mockery of financial fair play.
"Originally, for financial fair play, sponsorship deals had to be at the level of the market price and I don't know whether they will work or not.
"But what City do off the pitch, we've spoken about many times.
"On the pitch, they are an advert for football that's always good to see."