After pulling off a tremendous win over Ireland, last year's Six Nations champion and Grand Slam winner, England will be the heavy favourite to beat a French team that began its campaign with a dismal defeat to Wales.
France led 16-0 in Paris, but then gifted Wales two tries and was beaten 24-19.
England wing Ashton, who enjoyed a stint in France at Toulon, told the media: "The speed of their domestic game is definitely affecting the step-up to international level.
"The Top 14 is a slow, stop-start game. When you're in an international game it’s the highest intensity it could possibly be whereas their league isn't at that level. I'm speaking from experience. It's not anywhere near."
"Maybe that step-up shocks them in that first couple of games but they will get up to speed very quickly.
"I'd definitely say the Premiership is a lot more intense. The ball is in play a lot more and the whole game is a lot quicker."
Looking ahead to France's visit to Twickenham, Ashton said: "It will be an angry French team, desperate to make up for the last 20 minutes of that game against Wales.
"They will be up for the game against us more now than they would have been had they got the win. A lot of the French game is based on emotion but they’ve got a lot of good players in there too.
"If we know anything about the French, it is that they love a reaction. Their backs are against the wall and we expect nothing less from them really than putting everything into the situation. They’ve got to get a win and make up for last week."