Order Of St George has been handed joint top weight of 58kg (9st 2lb) for the Emirates Melbourne Cup at Flemington on 1 November.
Aidan O'Brien's charge suffered a shock reverse in the Irish St Leger last Sunday, but has still heads the weights with Andreas Wohler's 2014 Cup hero Proctectionist.
Racing Victoria chief handicapper Greg Carpenter admits the European-trained pair have been set a stiff task if they line up in the Group One.
He told www.racing.com: "There have been 23 original topweights contest the Melbourne Cup since Comic Court's win in 1950 and none have placed, so Order Of St George and Protectionist would rightly earn their place among the Cup's true greats if they were to be successful.
"The handicap presents a challenge to both Order Of St George and Protectionist, however, they have earned their position at the head of the weights based on their performances over the past 12 months."
Willie Mullins' Wicklow Brave was the horse to inflict defeat on Order Of St George at the Curragh and he is also in the Melbourne Cup reckoning after being given 55kg (8st 9lb) for the two-mile Group One.
Michael Bell's Big Orange and the French-trained Erupt both sit on 56kg (8st 11lb), while O'Brien's Bondi Beach and Michael Stoute's Exosphere are both on 55kg (8st 9lb).
Godolphin trainer Charlie Appleby's Scottish has 54.5kg (8st 8lb) while Ed Dunlop's Trip To Paris, who finished fourth in the Melbourne Cup last year, is on 54kg (8st 7lb)
O'Brien's Great Voltigeur Stakes winner Idaho has been given 53kg (8st 5lb) following his St Leger mishap, with Doncaster third Housesofparliament allotted 50kg (7st 12lb).
Defending champion Prince Of Penzance has been allocated 56.5kg (8st 13lb)as he bids for back-to-back successes.