A photo of the stopper and the EDL founder was posted by a Robinson supporter on Twitter.
Ederson wrote “don’t be a liar” after it was claimed he was a follower of Robinson.
Danny Thomas, a bodyguard for Robinson wrote: “Tommy Robinson meeting City’s golden boy @edersonmoraes93 last night, has his full support while in Manchester.”
Robinson, whose real name is Stephen Yaxley-Lennon, was a joint founder of the right wing English Defence League.
“I definitely not support this guy or his ideas”
With the tweet going viral, Ederson replied saying that he thought the photo was with a fan.
He wrote: “People have made me aware of who this guy is.
“I definitely not support this guy or his ideas.
“He just stopped me for a picture. I had no idea who he was…(do not be a liar).”
City fans then slammed Robinson for claiming he was supported by their keeper.
One wrote: “Tommy Robinson is scum claiming Ederson supports his views.”
Another fan added: “Tommy Robinson is a tosser.”
One more wrote: “Tommy Robinson is such a snake isn’t he. Well done Ederson.”
Ederson has been a massive success at the Etihad since his £35million move in 2017.
He has provided solidity at the back as City target their second successive Premier League title.
Before he tweeted, many had already doubted that Ederson knew who he was posing alongside.