A pilot tasked with flying a 'Moyes out' banner over Old Trafford says his company received the call two days ago - shortly after United went down 3-0 at him to rivals Manchester City.
Air Ads' chief pilot Chris Mustow also told ITV News' Ian Payne that, while the company had to be wary of public order issues, he was confident "we're not going to cause a riot".
More top news
Weather will be settled with with some sunshine and feeling cold
A bus carrying school children has crashed in Italy killing at least 16 people.
Tens of thousands of people are expected to join demonstrations on Saturday in cities around the world in support of women's rights.