Williams defends switch to union

Williams trained with Toulon for the first time on Wednesday

Former New Zealand star Sonny Bill Williams said the lure of a lucrative new deal was the reason he walked out on his contract and switched codes.

The 23-year-old was only one year into a five-year deal with his NRL side Canterbury Bulldogs.

But he provoked a furious response in Australia after signing with Toulon.

"If a bus driver is on $40,000 and gets offered a lot more to go somewhere else, what do you think they're going to do?" he said.

"Are they going to change bus companies? Or are they going to sit there and say, 'all these people want me to stay here because I'm the best bus driver around'. It's just common sense."

Williams has signed a one-year deal with Toulon, one of the biggest spending clubs in France, and has the option of a second season.

He trained with his new team-mates for the first time on Wednesday and could make his union debut at inside centre in a friendly against Carque-Hyeres on Friday.

606: DEBATE What can the NRL do to stop this turning into an exodus? BBC Sport's Phil Harlow

The Bulldogs and the NRL are launching legal action against Williams, with the game in Australia worried that his departure - which came hot on the heels of Kangaroos centre Mark Gasnier's move to Stade Francais - could spark an exodus of their top talent.

Union clubs in Europe - and particularly in France, where there is no salary cap - have already raided southern hemisphere rugby union for a string of top players.

Toulon have the likes of Jerry Collins, Anton Oliver, and George Gregan on their books, while star names like Doug Howlett, Byron Kelleher, Carl Hayman and Aaron Mauger have all moved to Europe.

Williams said he wanted to play for New Zealand in the future, with All Blacks legend Tana Umaga - his coach at Toulon - provided him with all the inspiration he needed.

Williams' departure has not gone down well in Australia

"You know, I'm with an icon, Tana Umaga, who I really think I can learn a lot from, and I want to play for the All Blacks one day, so that keeps me motivated," he said.

"One day I want to be the best centre in the world."

Williams said he believed NRL players were not being adequately rewarded and hoped his decision would highlight their plight.

Hopefully some good can come out of what I've done and it wakes everybody up and they realise that something needs to be done," he stated.

"What I've done, it's shown it's just not about me, it's about the boys getting a fair go.

"It's about them having the balls to stand up for themselves and get what they should be getting.

They don't care about me - the clubs treat us like cattle Sonny Bill Williams on the NRL clubs

"Because if we're going to be getting treated like that, why can't we treat the clubs like that?

"I'm one of those young kids that used to love watching everything about rugby league.

"But being at the club and seeing what goes on behind the scenes, I see that it is just a business. They don't care about me. They treat us like cattle.

"I'm no coward you know. I stood up for myself and I stood up for player rights."

Williams had been touted as having the potential to go down as one of rugby league's all-time greats.

The loose forward announced himself on the international scene in 2004 with a series of superb displays for the Kiwis but a series of ankle, shoulder and knee injuries have curtailed his appearances in the last few seasons.