Ashton believes the Manchester City midfielder is a class act but rates Fernandes ahead of him because of the goal threat the Portuguese international provides.
Speaking to talkSPORT, Ashton claimed: "I think Fernandes has already overtaken De Bruyne. You can see the difference when [Sergio] Aguero doesn't play for Man City.
"You can see the difference in De Bruyne, in terms of he looks like a frustrated figure in a lot of the games. He's still class, of course, as he’s got seven assists this season and the same as Bruno.
"It's that goal tally I think that Fernandes brings you. That goal threat that’s the difference between him and Kevin De Bruyne and that's why I'd pick him and why I think he's gone ahead of him as, for me, the best player in the Premier League."
De Bruyne recently addressed comparisons with Fernandes, telling Sky Sports : "He's a wonderful player. He came in and he gave United a different momentum.
"They were struggling last year, I know they had some games where they won against good teams but the consistency wasn't there last year for them.
"That's much improved this year and Fernandes is a big reason for that. He's a guy who makes football look fun. We're pretty similar in a way but I don't compare myself to other players. I enjoy other players but I never compare."
Both players have registered seven Premier League assists this season, with only Tottenham Hotspur star Harry Kane providing more with ten.
However, Fernandes has scored ten goals to De Bruyne's two, with the Belgian's two strikes coming from the penalty spot while Fernandes has netted four penalties.