Niall Horan

Niall Horan

Simon Cowell has slammed Niall Horan.

The music mogul was not happy when Niall chose to sign a solo deal with Capitol Records US rather than his Syco label and he says Niall would have gotten a number one if he had stayed with him.

Speaking about Niall's debut solo single, 'This Town', which reached number nine in the UK charts, Simon told the Sunday Mirror: "He probably would have had a number one single if he'd stayed with me.

"But you know who does have a number one this week? James Arthur. Very pleased he's back with us with a fantastic record. Hashtag loyalty."

Niall recently signed his huge record deal with Capitol US, a division of the Universal Music Group, just weeks after Simon predicted that the "loyal" star would join Syco as a solo singer.

A source previously said: "Simon has made no secret of his expectations for Niall to stay loyal to him and has been desperately trying to keep him as a solo act with plans to turn him into a Justin Bieber style artist.

"They've worked together closely since day one and have always had a strong relationship, but Universal offered a lot of money.

"Simon's likely to be so frustrated Niall has gone to a rival."

Simon - who guided Niall and his One Direction bandmates to fame after discovering them on the UK 'X Factor' - was left embarrassed after insisting that Niall, 23, would sign with him.

He said: "I think they're all gonna do great. Niall is the most loyal. We are expecting to announce something soon with him. I've always known he's loyal."

Niall's defection came after Liam Payne chose to sign his own solo deal with Capitol UK rather than Sony, where One Direction have been with imprint Syco for the past six years.

He said: "I worked with these guys for six years, so I always hoped they would all stay within what I call the Sony family, but I think only one won't."

Simon added that he "always knew" the group - which also comprises Harry Styles and Louis Tomlinson - would want to try to forge careers outside of One Direction and he hoped "that everyone would do it with us".