Potential Melbourne Cup runner Trip To Paris is a late entry for the Gold Cup at Royal Ascot.

Trainer Ed Dunlop is hoping the Chester Cup winner can raise his rating and earn the right to accompany Red Cadeaux to Australia in the spring.

Red Cadeaux has finished runner-up three times in the Melbourne Cup.

With slight doubts about the participation of the market leader Forgotten Rules because fast ground on Thursday, Dunlop and the owners, the La Grange Partnership, felt it was worth paying the STG35,000 ($A70,000).

"Following hours of deliberation, the decision has been made to supplement Trip To Paris for the Gold Cup on Thursday," said on his website.

"This hasn't been an easy call, with 35,000 (pounds) a hefty sum of money, but he's a young, progressive stayer who enjoys quick ground.

"In all likelihood there will be a few significant defections with the ground good to firm and the forecast dry.

"His owners are keen to run and it's impossible to knock such a sporting decision - here's hoping it proves a fruitful one."