Money continued to pour in today for Irish Derby winner Grey Swallow ahead of this Sunday's Prix de l'Arc de Triomphe but the chances of Mubtaker making the trip to Paris were described by Marcus Tregoning as "50-50".
Grey Swallow, who has to be supplemented for the Longchamp showpiece tomorrow, was the best-backed horse today with Coral, who cut the Dermot Weld-trained three-year-old to 7-1.
Weld said today: "He will be supplemented in the morning and a final decision will be made on Friday after we have monitored his health."
William Hill reported support for Andre Fabre's Prix Niel winner Valixir, and the colt was cut from 12-1 into 10-1.
Tregoning indicated that a decision over Mubtaker's participation in the Group One contest would be made after he had talked to the horse's owner Sheikh Hamdan tonight.
Weld took out veteran stayer Vinnie Roe at today's latest forfeit stage, but has kept him in the Prix Cadran on the same card.
Richard Hannon has also removed Nysaean from the field, which went down from 27 to 21 possibles, although none of the market fancies were absentees.
As expected, Elie Lellouche reduced his quartet to two in the shape of Vallee Enchantee and Policy Maker, while the others to come out were Whortleberry and Turkish runner Grand Ekinoks.
The field is still one above the permitted amount of runners and with Thursday's supplementary stage to come, where French Derby winner Blue Canari is expected to be added to the field by Pascal Bary together with Grey Swallow and possibly Quiff, some connections face the prospect of being balloted out.