The William Haggas-trained four-year-old left Investec Oaks heroine Forever Together trailing in her wake when running out a hugely impressive winner of the Pretty Polly Stakes at the Curragh last month.
She then appeared at Goodwood in the Nassau Stakes and emerged with plenty of credit after finishing second to the three-year-old Wild Illusion, to whom she was conceding 8lb.
Urban Fox is on level weights with each of her nine rivals in France this weekend and Haggas reports his star filly in rude health.
Haggas said: “I’ve no idea what conditions are like, but I’m happy with the filly.
“She’s in good form and I’m very pleased with her going into the race.
“She deserves to take her chance, so fingers crossed.”
Urban Fox is joined on the trip across the Channel by the Martyn Meade-trained Wilamina, who was not too far behind when fifth in the Nassau.
Meade said: “She ran well at Goodwood behind Urban Fox and she’s beaten a couple of others that she meets on Sunday.
“I think the trip and track will suit her, she’s in good form and there’s no reason not to have a go really.
“Frankie (Dettori) has ridden her a couple of times this year and was keen to have a go. It’s great to have him on board.”
The two Irish challengers are Aidan O’Brien’s Rhododendron and I’m So Fancy from Jessica Harrington’s yard.
Lockinge heroine Rhododendron was a disappointing last of six when favourite for the Nassau and is fitted with blinkers for the first time.
I’m So Fancy tests the water at Group One level for the first time after chasing home O’Brien’s Magical in the Kilboy Estate Stakes at the Curragh.
The home team includes the prolific Bateel, formerly trained in Britain by David Simcock but now with Francis-Henri Graffard, and Lady Frankel from Andre Fabre’s yard.