Robbie Williams is "jealous" of One Direction.

The singer joined British boy band Take That when he was just 16, and has many fond memories of first enjoying success. He wishes he was still a teenager so he could join One Direction, who have become worldwide stars.

"I'm jealous of them and I wish I was doing it all with them," he told BBC Radio 1. "I'm looking forward to seeing where the road takes them for many years to come I hope.

"They do perform like they've never met each other and there's a certain charm to that too. It's brilliant."

Robbie became a father for the first time this week when his wife Ayda gave birth to their daughter Theodora.

The 38-year-old singer is also set to release his ninth studio album Take the Crown - in November, and has jokingly threatened not to tour if the lead single Candy is a flop.

"I don't want to emotionally blackmail the whole of the nation but if Candy is not a hit, I'm not touring," he quipped. "I'm going to get all beardy and fat again - it's up to you if you want that to happen. It sounds like a hit to me but I've been wrong in the past."

Meanwhile, it has been reported that One Direction have made a staggering 100 million since appearing on The X Factor UK two years ago.

The claims have been made in a new chapter of Tom Bower's book about Simon Cowell.

Money from their albums, DVDs, merchandising and endorsements has seen them rake in huge profits for the band - Liam Payne, Niall Horan, Harry Styles, Zayn Malik and Louis Tomlinson.

This month the five-piece were unveiled as the new global face of Pepsi, in a deal reportedly worth 11 million, while their world tour is a sell-out.

Next year One Direction The Movie will be released and is expected to see their earnings rise further.