The unbeaten Dawn Approach features in 24 colts going forward in the 2013 Investec Derby, the premier Classic run at Epsom Downs on Saturday, 1 June.

Dawn Approach has already annexed the first Classic of the season, the QIPCO 2000 Guineas at Newmarket and will be attempting to become the 38th horse to win both Classics.

A son of the 2008 Investec Derby hero New Approach, Dawn Approach is the evens favourite with Coral, official betting partner of the 2013 Investec Derby Festival. His trainer Jim Bolger could also be represented by Trading Leather, who was runner-up in the Group Two Betfred Dante Stakes at York. Bolger's third leading three-year-old, Loch Garman, is set to contest the Irish Derby.

Speaking at York, the Irish handler said: "I am thrilled with my three top horses, Dawn Approach, Trading Leather and Loch Garman.

"We know the one that is better (Dawn Approach) – he is well. It is a toss-up between the other two.

"I think the only trials that matter were run in Coolcullen (on his stable's gallops). I'm ecstatic with them.

"With due respect for the winners of the Leopardstown trial and the trial here (York), we would be expecting to show serious improvement from a fitness point of view (Loch Garman and Trading Leather respectively)."

Ireland's champion trainer Aidan O'Brien, seeking his fourth Investec Derby victory following Galileo (2001), High Chaparral (2002) and Camelot (2012), has been in red-hot form during the trials season and has seven contenders remaining.

These include Ruler Of The World and Magician, who were successful in the Chester Vase and Dee Stakes respectively at Chester last week, as well as Lingfield Derby Trial scorer Nevis and Battle Of Marengo, who landed the Derrinstown Stud Derby Trial at Leopardstown. O'Brien could also be represented by Mars, a staying-on sixth behind Dawn Approach at Newmarket, Festive Cheer and Flying The Flag.

Further Irish interest could be provided by First Cornerstone (Andy Oliver), Galileo Rock (David Wachman) and Zand (John Oxx).

Andre Fabre was responsible for the last French-trained winner of the Investec Derby, Pour Moi in 2011, and is set to be represented this year by Ocovango. The Monsun colt is unbeaten in three starts at Saint-Cloud and was last seen out when taking the Group Two Prix Greffulhe on 4 May, the same trial Pour Moi landed before his Epsom Downs victory. Ocovango could renew rivalry with the Jonathan Pease-trained Bravodino, who was half a length back in second in the Prix Greffulhe, while fellow French trainer Freddy Head also has two contenders going forward, Eternal Ray and Qahir.

Further interest from the Continent is provided by German contenderSuperplex (Michael Figge), fourth behind Ocovango in the Prix Greffhule.

The last Northern-trained winner of the Derby was Dante in 1945 but there is a live contender from Yorkshire this year in the Elaine Burke-trained Libertarian, a shock 33/1 winner of the Dante Stakes.

The Sir Michael Stoute-trained Telescope, who was well-supported in the ante-post market but was forced to miss the Dante Stakes due to a late setback, remains engaged and could head straight to Epsom Downs following a racecourse gallop.

Mirsaale is the one horse in the field with proven form at Epsom Downs, having taken the Investec Derby Trial on 24 April and he is set to be a first runner in the Investec Derby for Newmarket-based trainer James Tate.

Completing the potential line-up are Jammy Guest (George Margarson) who lines up in the Listed Fairway Stakes at Newmarket tomorrow, Gold Medal (Richard Hannon), Ocean Applause (John Ryan) and Tinghir (David Lanigan).

The 2013 Investec Derby will have a prize fund of at least £1.325 million. There is one final chance for connections to add a horse to the field at the £75,000 supplementary entry stage on Monday, 27 May. Exciting German challenger Chopin, a 10/1 chance with Coral, is expected to be supplemented.