The chances of Lloyd Williams adding to his Melbourne Cup record of six wins are threatened by favourite Yucatan's wide barrier.

Leviathan owner Lloyd Williams' chances to extend his record of Melbourne Cup winners to seven have taken a hit with his Irish-trained horse drawing barrier 23, the second widest gate.

That does not concern Williams' son and part-owner Nick Williams who has played down the importance of barriers in Tuesday's 3200m-race.

"I must say I'm of the view that barriers don't matter in this race," Williams said.

"You've got five furlongs (1000m) before you have to turn. They sort themselves out by the time they get there.

"It is what it is, there's no point worrying about it.

"I've got a few simple things when you're looking towards trying to find the winner of this race and this horse is certainly ticking all the boxes at this point.

"We're proud Melburnians so this week means a lot to us.

Yucatan is trained by Aidan O'Brien who has won most of the major races around the world but the Melbourne Cup has eluded him.

His best result came a year ago when Johannes Vermeer finished second to the Williams-owned Rekindling, trained by O'Brien's son Joseph.

Aidan O'Brien was also thwarted by a Williams runner in 2007 when Mahler finished third to Efficient.

Yucatan rose to favouritism with his Herbert Power Stakes win while Williams also has shares in The Cliffsofmoher, third in the Caulfield Cup and drawn in gate nine on Tuesday.

"They just can't run home any quicker than what he ran home. So I think he's in good form," Nick Williams said.

One of 11 overseas-trained horses in the 24-horse field for the Melbourne Cup, Yucatan had eased from $4.50 to $5.50 by Sunday with the Marwan Koukash-owned Ian Williams-trained Magic Circle in to $8.50 and Godolphin's Cross Counter at $9.

Trained in England by Charlie Appleby, Cross Counter is one of three Godolphin horses in the race, with Avilius ($13) trained in Australia by James Cummings and Best Solution, also a $13 chance, by Appleby's Newmarket neighbour Saeed bin Suroor.

Koukash, who owned 2013 minor placegetter Mount Athos, has threatened to celebrate a win by stripping down to a tie and G-string.

Despite the publicity about his impending stunt, the millionaire English-based businessman takes his racing seriously.

"There are only two Cups I'd love to win, one is the Chester Cup and the other one is the Melbourne Cup," he said.

"I'm living the dream.

"Any owner in the world would dream of having a runner in the Melbourne Cup.

"Not to only have a runner but to have one of the favourites in the Cup, it's great."