Even Song is a heavy odds-on favourite for the Darley Irish Oaks but Saturday's feature has been the most lucrative of the Curragh classics for overseas based horses in recent years and a strong cross-channel raiding party looks poised to take on Aidan O'Brien's star.

Both Ajman Princess and Architecture were supplemented into the Oaks at a cost of €40,000 each at the latest declaration stage on Tuesday and they boost what could ultimately shape up into a five-strong British challenge on the €400,000 highlight.

Just one filly in the last seven years has managed to keep the Oaks in Irish hands and that sole home based winner, Bracelet, was a surprise 10-1 shot in 2014.

She was O’Brien’s fourth winner of the Curragh Oaks and even though Even Song holds almost all of the cross-channel entries on form - having had Ajman Princess, Architecture, We Are Ninety and Sovereign Parade behind her in Royal Ascot’s Ribblesdale Stakes - there is a noticeable willingness to take on the Irish favourite again.

The one filly among the British entries that Even Song hasn’t faced yet is Mick Channon’s Harlequeen who missed Ascot after her third to the O’Brien superstar, Minding, in last month’s Oaks at Epsom.

“She is in very good form and she didn’t surprise me at Epsom as I expected her to run a big race,” said Channon who has won with two of his three runners to date at the Curragh in 2016.

“Silvestre de Sousa is coming over as well and he knows her and that is a big help. She has only had the four runs in her life, but she has improved with each run. It looks a good race, but on her run at Epsom she deserves to take her chance,” he added of Harlequeen who was initially installed as a 12-1 shot by some bookmakers.

Even Song is as low as 2-5 however and with O’Brien training eight of the 19 entries left in the race, the Ribblesdale winner is unlikely to want for familiar company.

“Even Song had a little break since Ascot and we’ve been very happy with her. She seems to handle most types of ground and we are looking forward to running her,” O’Brien confirmed.

“I’ve been very happy with Somehow since Epsom and we just felt that she didn’t act around Epsom and we think the Curragh will suit her better and hopefully Seventh Heaven will be the same and better suited by the Curragh.

“Pretty Perfect won nicely at Cork and is after really progressing with every run and loves a mile and a half so she is another possible runner on Saturday,” he added.

Bookmakers believe that Ajman Princess could emerge as Even Song's big danger again after chasing her home at Ascot even though the Roger Varian trained star has finished runner up in all four career starts.

Varian isn’t bothered by that however and said: “I feel she is a filly who is progressing at a rate of knots and she will certainly not look out of place in Group One company based on her Royal Ascot form.

“I think the galloping nature of the Curragh will suit her and she is versatile in terms of ground. It looks like being just on the easy side at the weekend, which should not prove problematic.

“Obviously we have a length and a half to find with Even Song, and she sets a high form standard, but our filly is getting better all the time and I hope she can be very competitive.”

Ground conditions at the Curragh's round course are currently "good" although there are showers forecast in the coming days, something that perhaps won't suit Turret Rocks, one of four that Jim Bolger can choose from.

Hugo Palmer landed the Oaks with Covert Love last year and Architecture appears his No.1 hope this time despite finishing only eighth in the Ribblesdale behind her stable companion, We Are Ninety, in sixth.

“It didn’t work out for well either of them in the Ribblesdale. They were both too far back and too wide in a messy, slowly run race, and they were beaten three-lengths and five-lengths respectively by Even Song. If things go our way I hope they both stand a good chance,” Palmer said.

Joseph O’Brien may have the first classic runner of his training career although the 100-1 shot Way To My Heart is rated just 74 and is yet to win a race.

Four of Aidan O’Brien’s Oaks entries also figure among the possibles for Sunday’s Kilboy Estate Stakes, one of two Group 2 prizes with the Breeders Cup Juvenile winner, Hit It A Bomb a notable entry for the Friarstown Minstrel Stakes.

The former Group 1 winner G Force, now in the care of trainer Adrian Keatley after being removed from stud duty, has been supplemented into Saturday's Group 2 Kilfrush Sapphire Stakes.

Another Group 1 winner, Mecca’s Angel, also features among entries for the five furlong sprint.

Wednesday’s Irish action will see the Presidential colours return to Killarney when Aimhirgin Lass appears in the fillies handicap on Day 3 of the July festival.

Aimhirgin Lass appreciated a cut in the ground when winning at last year's festival and a step up in trip could be what she requires to beat the topweight Ringside Humour who is on a hat-trick but has to concede a stone to the John Oxx runner.