Racing Victoria has conceded that the number of internationals to the spring carnival could slow because of the expensive gamble connections need to make.

While millions of dollars in prize money is on offer, it can cost up to $120,000 to bring a horse from overseas with no guarantee of a start in the big events - a situation unlikely to change, according to chief handicapper Greg Carpenter.

"If you go to any other international race virtually in the world the club invites you to go, they pay for you to go, the owner, the trainer, the jockey, and they cover all your expenses," Carpenter said.

"The Melbourne Cup is the staying championship of the world. No-one comes here on a promise.

"Every horse knows that they pay their own way, they pay the way of the jockey, the trainer, the owner, the strapper.

"It is an expensive exercise for horses to come from Europe and run in the Melbourne Cup.

"But we don't invite horses, we don't pay for them to come, we don't guarantee horses a spot in the field and I think that's one of the great strengths of the race."

He said the Melbourne Cup needed to maintain its integrity whatever the class of horse and that may lead to some owners having second thoughts in the future.

"It's why we say it doesn't matter where a horse is owned or trained or where it's raced - the best 24 get there on the day," Carpenter said.

"It may well be a cautionary tale for international horses if they come all this way and don't get into the field.

"And certainly that was the case last year. The last horse in was an international and the first horse out, the horse that was 25 last year, was also an international.

"It is a level playing field. We don't favour or make any promises to internationally-trained horses and at the end of the day they all understand that they come out here hoping to get into the race but certainly not guaranteed a spot," he said.