Star British horse Cracksman headlines a list of 13 international horses invited to take up the challenge against champion Winx in the Cox Plate.

The Moonee Valley Racing Club issues invitations to some of the best-performed middle-distance horses in the world in a bid to attract them to run in the weight-for-age showpiece in October.

This year's Cox Plate (2040m) has had a significant prize money injection from $3 million to $5 million and is expected to feature champion Winx trying to win the race for a record fourth time.

The John Gosden-trained Cracksman won the Champions Stakes at Ascot in 2017 and has returned with two Group One wins already this year in the Prix Ganay and Coronation Cup.

The horses invited are from the United Kingdom, United Arab Emirates, Japan, France, United States and Ireland.

Champion Irish trainer Aidan O'Brien has prepared the only northern hemisphere-trained winner of the Cox Plate, Adelaide in 2014, and three horses from his stable - Lancaster Bomber, Saxon Warrior and Mendelssohn - have been invited this year.

"With the recent $2 million prize money injection to our great race for the first time since 2002, we are confident we can entice horses on the world stage to compete at the Valley in what is now the richest Group One turf race at 2000 metres in the world," MVRC chief executive Michael Browell said.

"Working with the MVRC Committee and Paul Bloodworth and the team at Racing Victoria, we have identified what we believe to be the best weight-for-age horses and we hope they are keen to take on Winx and create a brilliant spectacle."

Paul Bloodworth, RV general manager international and racing operations, said quarantine issues ruled out inviting star Hong Kong horses.

"However this is something we are hoping to rectify in the near future," Bloodworth said.

COX PLATE INVITEES:

* CRACKSMAN (country UK), trained by John Gosden

* BENBATL (UAE), Saeed Bin Suroor

* ALMOND EYE (Japan), Sakae Kunieda

* RECOLETOS (France), Carlis Laffron-Parais

* MOZU ASCOT (Japan), Yoshito Yahagi

* POET'S WORD (UK), Sir Michael Stoute

* LANCASTER BOMBER (Ireland), Aidan O'Brien

* YOSHIDA (USA), William Mott

* THUNDER SNOW (UAE), Saeed Bin Suroor

* EPOCA D'ORO (Japan), Hideaki Fujiwara

* SAXON WARRIOR (Ireland), Aidan O'Brien

* MENDELSSOHN (Ireland), Aidan O'Brien

* PERSIAN KNIGHT (Japan), Yasutoshi Ikee.