Dortmund chief wants UEFA action against Man City

City regularly record massive losses subsidised by their owners, and have signed a number of deals with organisations closely linked to the club.

“UEFA must find the thin line between sponsorship and excessive back-door funding – they must show strength to expel big clubs,” he said.

“No tycoon should be allowed to pump crazy money into a club with sponsorship from five companies he controls. If that happens, financial fair play will fail.

“I would not even welcome him (City owner Sheikh Mansour). What if the sheikh, as shown by Malaga, lost interest?”