More than 100 horses remain in contention to win the first WS Cox Plate of the post-Winx era, headlined by current favourite Mystic Journey as well as 17 internationals from the northern hemisphere.

First declarations for the $5 million Cox Plate (2040m) were taken on Tuesday with 102 horses, including 36 Group One winners, still paid up for the weight-for-age race at The Valley on October 26, a rise of 39 from the same stage last year.

The now-retired Winx won the Cox Plate the past four years.

The Adam Trinder-trained Tasmanian mare Mystic Journey heads the current Cox Plate market at $4.40 and will be striving to claim her eighth straight win when she runs in Saturday's Makybe Diva Stakes at Flemington, the second start of her current campaign.

Mystic Journey, winner of the All-Star Mile and Australian Guineas, is one of four locally trained horses already in the running to claim a $1 million bonus should they win the Cox Plate, along with Memsie Stakes winner Scales Of Justice, Feehan Stakes winner Homesman and Australian Cup winner Harlem.

The international first acceptors include the Japanese pair Lys Gracieux and Kluger and the David Menuisier-trained Danceteria whose connections have all accepted invitations from the Moonee Valley Racing Club to contest the Cox Plate.

Irish trainer Aidan O'Brien, who won the 2014 Cox Plate with Adelaide, has seven horses still in the mix for the Cox Plate including Anthony Van Dyck and Circus Maximus.

There are 19 three-year-olds remaining in the entries while some of the notable withdrawals at the first acceptance stage include Everest contenders Arcadia Queen and Enticing Star.

First acceptances have also been taken for the Group One Caulfield Guineas which has 112 three-year-olds still in the running, while 110 three-year-old fillies have been paid up at the first acceptance stage for the Group One Thousand Guineas.