Irish champion jockey Jamie Spencer has resigned from Ballydoyle after just 12 months in a job that has been described by some as the best in racing.

Spencer replaced Mick Kinane as Ballydoyle stable jockey a year ago, after a spell as second jockey behind Frankie Dettori at Godolphin. Despite winning the Irish jockeys’ title, he had a difficult season, picking up several bans and facing criticism for his rides on horses such as Powerscourt in the Arlington Million and Antonius Pius in the Breeders’ Cup Mile.

Rumours that he and Ballydoyle could part ways had first appeared on the Internet in January, although the stable only confirmed the news on Sunday.

“Jamie Spencer has informed us of his decision to resign as stable jockey,” Ballydoyle spokesman Richard Henry said in a statement. “Jamie is a young jockey with a lot of talent and he has a long career ahead of him. All of the team at Ballydoyle wish him the very best.”

Spencer was full of praise for owners John Magnier and Michael Tabor, for whom he will ride Rosecliff at Lingfield on Saturday. However, he wasn’t as effusive about trainer Aidan O’Brien, fuelling speculation that a rift between the two had eventually led to Spencer’s resignation.

But the jockey denied any disagreement with O’Brien and put his decision down to a mix of personal and professional reasons. Speaking at Lingfield on Wednesday, he told reporters he wanted to move back to Britain, partly because he enjoyed the thrill of riding a race every day and partly because of his impending marriage to TV presenter Emma Ramsden.

“Peace of mind means a lot in life, no matter how much money you have. If you don’t have peace of mind, or go to bed content at night, then you’re doing the wrong thing,” he said. “At the end of the day, there’s more to life than racing.”

Spencer made his freelance debut riding for David Loder and is expected to race soon for former trainer Luca Cumani. John Murtagh, who won the 2002 Derby for Ballydoyle on High Chapparal, is the current favourite to replace Spencer as their stable jockey, followed by Kieren Fallon and Darryll Holland.