Adrian Maguire has announced that he is to step down from his position as stable jockey to David Nicholson with immediate effect.

A statement from Maguire said: "Because of repeated press speculation about my situation at Jackdaws Castle, I have asked Colin Smith if he will release me from my retention at the yard.

"After much discussion he has agreed and I will become a free agent with immediate effect.

"However, I will not be leaving Jackdaws Castle and I would hope that I would continue to ride for the majority of the owners who have so far been very supportive, subject to the wishes of David Nicholson.

"I very much regret having had to take this action, having had the support of David Nicholson and Colin Smith, but this seems to be the only way of clearing the air, stopping the speculation and not having all my rides under a press microscope."

Maguire's position as number one at the yard had come under apparent threat in recent weeks, when some of the stable's owners expressed a preference for their horses to be ridden instead by Richard Johnson.

Johnson partnered Darren Mercer's Escartefigue into second place behind Teeton Mill in Saturday's Pertemps King George VI Chase, while Maguire was aboard outsider Mulligan, who was pulled up. However Nicholson insisted that Maguire remained the stable's first-choice pilot.

A report in yesterday's London Times claimed that a "heated row" had taken place between Smith and Nicholson over Maguire's treatment. Jackdaws Castle is a state-of-the-art training establishment, owned by Smith's company Ford Farm Racing.

Speaking yesterday, Smith said: "If Adrian jacks it in as stable jockey at the yard in the next few days over what's been happening - and I don't blame him if he does - there will be no retained jockey at the yard for the rest of this season and possibly next season as well."

Maguire's career as a jockey has been blighted by a series of riding accidents.