FORMER Newport ace Ofisa Tonu'u believes Rhys Webb's battle with Aaron Smith on Wales' tour to New Zealand will go a long way towards deciding who is the world's best scrum-half.

Warren Gatland's squad start their preparations for the three Tests against the All Blacks in earnest next week.

They will work at their Vale of Glamorgan headquarters ahead of the friendly against Six Nations champions England at Twickenham a week on Sunday.

The next destination is Auckland as they prepare for a vital Eden Park opener against New Zealand that will set the tone for the series.

Webb will be a key figure against the world champions following his return from the foot injury that cruelly crushed his England 2015 dreams.

The 27-year-old returned in the final two fixtures of the Six Nations, scoring a sixth Test try when winning his 18th cap against Italy, and finished the season strongly with the Ospreys.

And Tonu'u – who made 45 appearances as a scrum-half for the Black and Ambers between 2001 and 2003 – believes the number 9 will be to the fore for a Wales side desperate to cause an upset.

"It's going to be a tough three Test series against Wales," the former Samoa and New Zealand international said to allblacks.com.

South Wales Argus:

"Often when northern hemisphere teams come down here they are going through the motions at the end of a long season – but this Wales side is different.

"They have targeted this tour as a chance to get their first win over the All Blacks since 1953 and have named a very strong squad.

"In Rhys Webb they boast a skilled distributor and dangerous runner. It will be a great challenge between him and Smith, and one that may decide who is the world's number one half-back."

Webb is backed up by Gareth Davies and Lloyd Williams for the tour, which also pits Wales against the Chiefs in a midweek clash between the first and second Tests.