A number of horses have been grounded in Melbourne after their flight to Perth was cancelled because of a fuel leak.

Chris Calthorpe from Air Horse Transport said 18 horses had been loaded aboard the plane which was ready for pushback when the leak was discovered.

"They tried to fix it but obviously the horses are the number one priority in that situation," Calthorpe told RSN927.

"Once they found the problem and it was going to be a bit of a monumental task to fix it, we got on the front foot and organised to get the trucks back, get the horses off and delay the flight 24 hours."

A number of Warrnambool-trained horses, including Gailo Chop, spent the night at Caulfield ahead of Tuesday's rescheduled flight after a plane from Malaysia was sent to Melbourne.

The Perth carnival steps up a notch on Saturday with the running of the Group One Railway Stakes at Ascot.

Three runners in that race were aboard the abandoned flight, Best Of Days, Reykjavik and Manolo Blahniq, along with WA Guineas contender Widespread.

Calthorpe said he had spoken to most trainers involved who said the horses seemed happy following Monday night's ordeal.

Matthew Williams, who trains Gailo Chop, says he has time up his sleeve as the gelding is not due to run until the Kingston Town Stakes (1800m) on December 7.

But he said it may not be ideal for those horses running on Saturday.

"They probably missed a bit of their night feed and not drinking what they would be drinking if in their stable at home," Williams said.