New Zealand Prime Minister John Key has branded English rugby as a 'bunch of wannabes' after reports that England will wear an all-black away strip with Maori symbols on it at the World Cup this year.

Although England usually play in white, their apparel sponsor Nike are due to unveil a new away kit on August 1 and both the shirt and the shorts of the new strip are jet black with no other colour except for the Red Rose badge.

It is officially England's change strip but apparently it will be worn for their three World Cup warm-up matches in August and for their opening pool match against Argentina in Dunedin on September 10, and could also be used later in the tournament.

The decision to copy New Zealand's iconic All Black jersey, which has a 127-year history, has already triggered a furious response from rugby traditionalists in New Zealand who see the cheeky marketing ploy as an insult to the All Blacks' rich tradition, with Key being particularly vocal.

"I think it's a bunch of wannabes actually, there's only one team that wears black with pride and that's the All Blacks," he told 3news.co.nz.

It is understood the kit will be used for the first time against Wales at Twickenham on August 6 and then in the return match in Cardiff the following weekend. The kit will also be worn in Dublin for England's last warm-up game against Ireland at the Lansdowne Road on August 27.

Even England's World Cup training gear has a Kiwi twist, with a red rose crest on the shirt surrounded by ancient Maori symbols and decorations.

However, the English Rugby Football Union (RFU) have spoken to their New Zealand counterparts, who indicated they have no official objection on the agreement that England would wear white if they play the All Blacks during the tournament.

NZRU chief executive Martin Sneddon said: "The All Blacks should take it as a compliment to them, ourselves, as a country believe in the power of the jersey, the power of the black, and maybe that is what England is trying to get their hands on."

All Black captain Richie McCaw has refused to be drawn into the emotional debate and explained that he prefers to remain focused on the job on the pitch rather than sideshows.

"People play games I suppose about why they are doing these things, but not a biggie really," he said.