It's crunch time this weekend for international Melbourne Cup hopefuls Simenon and Mount Athos when they contest key staying races in the UK

The Willie Mullins-trained Simenon, runner-up in the G1 Ascot Gold Cup in June, heads a field of Melbourne spring carnival contenders in the Lonsdale Cup at York on Friday while Luca Cumani's Mount Athos will be facing his big test for a return to Australia in the March Stakes at Goodwood on Saturday.

Mullins, renowned as Ireland's champion jumps trainer, has been keen on a trip to Australia with Simenon since the stayer fought out the finish of the Ascot Gold Cup with the Queen Elizabeth's gallant mare Estimate, eventually going down by less than half a length.

The G2 Lonsdale Cup will be Simenon's first start since the Gold Cup, facing six rivals over the Melbourne Cup trip of 3200m.

Simenon was tried over the jumps last year before reverting to flat racing with Mullins being well advanced in his plans for an Australian trip.

"We're planning it as if we are going to get in the Melbourne Cup and we've entered him in all the prep races out there.

"It does depend on how he gets on at York, though.

"He has had a break but I'm very pleased with him and everything seems to be going well."

His rivals include last year's Lonsdale Cup winner Times Up and the Goldolphin pair Colour Vision and Ahzeemah.

Colour Vision won the 2012 Ascot Gold Cup but was only fourth behind Estimate this year before a flat seventh in the Goodwood Cup.

Ahzeemah has recent placings at Goodwood and Newmarket to his credit and has never finished worse than second in his last nine starts.

The Richard Fahey-trained Glen's Diamond, winner of the Yorkshire Cup in May, is also under consideration for a trip to Melbourne despite a recent failure in the Goodwood Cup.

Mount Athos, fifth in last year's Melbourne Cup, will need to turn around his form in the Listed March Stakes (2816m) to confirm a return trip to Melbourne this spring.

Since wining first-up at Chester he has been average running fifth in the G2 Hardwicke Stakes (2400m) and mid-field effort from the rear in the Goodwood Cup (3200m).

Mount Athos faces six rivals and will be ridden for the first time by Richard Hughes.

“Last season was a good one for him with three wins on the bounce before his effort in the Melbourne Cup,” Cumani said.

“We will start planning his trip after the weekend and we are hoping he runs well.”

Cumani has won the March Stakes twice in the last three years with My Quest For Peace last year and Drunken Sailor in 2010.

Mount Athos is joint top-rated in the March Stakes with the Wiliam Haggas-trained Harris Tweed, a last start six-lengths winer at Goodwood.

Godolphin is represented by Songcraft while Tac De Boistron makes his debut for Marco Botti having been off the track since finishing 23rd behind Green Moon in the Melbourne Cup last November.