Australian trainer Paul Messara will be reunited with his stable star Ortensia in England this weekend, confident the mare is ready to claim her third Group One on as many continents.

Messara leaves Sydney on Friday to oversee Ortensia's final preparations for the Nunthorpe Stakes (1006m) at York a week later.

The Australian sprinter's overseas campaign has been highlighted by a Group One win in the Al Quoz Sprint (1000m) in Dubai in March and a Group Two victory in the King George Stakes (1006m) at Goodwood on August 3.

In between the two victories, Ortensia finished ninth in the King's Stand Stakes at Royal Ascot and fourth in the July Cup, both on rain-affected ground.

"The reports are really good. She worked on Tuesday morning and worked really well," Messara told AAP.

"She has come through the last race extremely well and as long as we get a dry track she'll be very hard to beat.

"She's close to favouritism now in the market, She meets all the horses she beat last start seven pounds (3kg) better and the two other chances I guess are Sole Power and Bated Breath.

"They are probably the best two other sprinters over there. She beat Sole Power in Dubai and she'll have a chance to beat Bated Breath hopefully on Friday."

Messara has scheduled Ortensia to have her final major piece of work early next week.

"She'll work again on Monday morning, do her last piece of work then," he said.

"She'll travel up to York on the Thursday night and be ready to go on Friday.

"It's only been three weeks between runs so it's been quite easy to program her workouts and just really have her spot-on for the Nunthorpe."

Ortensia's first Group One came in the Winterbottom Stakes in Perth last summer, prompting the ambitious overseas campaign.

"It would be fantastic," Messara said.

"Three continents, three Group Ones. It would be a huge result. It makes her also a very valuable broodmare."