MELBOURNE (AFP) -- Irish-trained Vauban heads into Tuesday's Melbourne Cup as favorite in Australia's "race that stops a nation", but faces a looming threat from in-form Gold Trip who is targeting back-to-back wins.

Held on the first Tuesday of November since 1876, the punishing 3,200 meter (two-mile) handicap at Flemington is regarded as the ultimate test of stamina and staying power.

With Aus$8 million (US$6 million) at stake, the winner of the 24-strong field will bank Aus$4.4 million and instantly become a household name in Australia where the race is a cultural institution.

Carrying 55kg, Vauban has won his last two races, including a demolition of Melbourne Cup rivals Absurde and More Felons at Royal Ascot this year.

That shot the six-year-old gelding to the top of the markets, with its status reinforced by a comfortable win at Naas in Ireland.

As adept over the hurdles as on the flat, Vauban's odds shortened further after an impressive gallop in training at Flemington last week.

Drawn in barrier three, his odds have since drifted but he remains the horse to beat, according to bookmakers.

Master trainer Willie Mullins has come close to glory before, finishing second with Max Dynamite behind Prince of Penzance in 2015 and third to Rekindling two years later.

He believes Vauban, who was foaled in France, could be his best opportunity to finally take the win.

"I think he's as good as Max Dynamite, maybe better, but we'll find that out on Tuesday," he said.

"He's our strongest chance and may be my strongest chance ever."

English jockey Ryan Moore, who won in 2014 aboard Protectionist, has been entrusted with the reins.

British stallion Gold Trip is currently joint second favorite and will start as the top weight at 58.5kg, a kilogram heavier than 2022 when he streaked home first ahead of Emissary.

Way more confident

Star jockey James McDonald, who rode Verry Elleegant to victory in 2021, will be in the saddle of a horse that had by a strong showing in the recent Group 1 Caulfield Cup and a commendable finish in the Cox Plate.

Co-trainer Ciaron Maher is upbeat on what is forecast to be a hot day, but with the chance of thunderstorms which could soften the track.

"The track's probably going to be a little bit firmer (than last year) and he's got a little bit more weight. So he needs to be better to win, but I think he is," he said.

"I'm more confident, way more confident."

Drawn alongside Vauban in barrier two, the seven-year-old is seeking to become the first back-to-back winner since the legendary Makybe Diva won three-in-a-row between 2003-2005.

Mark Zhara, who rode Gold Trip to the win last year, has instead opted for Caulfield Cup winner Without a Fight, which has firmed to be joint second favorite.

Vauban stablemate Absurbe, with leading Hong Kong rider Zac Purton on aboard, is also tipped to challenge, as is the Joao Moreira-ridden Soulmate.

Veteran jockey Damien Oliver is chasing a record-equaling fourth Melbourne Cup win in his last ride before retiring.

But the 51-year-old is rated only an outside chance of a fairytale send-off on Alenquer to match the exploits of Bobbie Lewis and Harry White.

Kerrin McEvoy is also looking for a fourth win, this time with Ashrun, but is similarly not considered a serious threat.