Cape Town - Dan Carter believes Beauden Barrett is still the best in the flyhalf position for the All Blacks, despite stiff competition from Richie Mo'unga.

Mo'unga has been in sparkling form, guiding the Crusaders to a ninth Super Rugby title, prompting many to suggest it was time he was given a shot in the coveted All Black number ten jersey.

While Carter paid tribute to Mo'unga's 'fantastic season', the three-time World Player of the Year believes Barrett's experience and leadership still give him the the edge.

"It's obviously hotly debated at the moment and credit to Richie Mo'unga for putting his hand up over a fantastic season," Carter told the New Zealand Herald.

"It's hard to go past what Beauden's achieved over the last couple of years. A lot of the All Blacks' success has come because of his performances. He's a leader of the team now."

Barrett is the current holder of back-to-back World Rugby Player of the Year crowns. But it is Mo'unga who has stolen the limelight in Super Rugby this season, with Barrett's form slightly underwhelming in contrast.

"I've been in that position with young guys nipping at your heels. It makes you work harder and appreciate your position in the team more," Carter added.

"It's great there's competition. Damian's not a bad talent as well. It's great the All Blacks have such depth."