Former World Cup winning coaches Steve Hansen and Jake White have given their backing to a new 12-a-side rugby format which has been launched.

The 'World 12s' is promising "unprecedented prize money" and claims it can bring nearly €300m to the game of rugby within five years.

A number of prominent names from rugby have given their backing to the proposed annual tournament, which organisers are hoping will get under way in August 2022 in England, and they have begun consultation with "key global rugby stakeholders".

The format of the competition will see eight new franchises compete in a round-robin format across three concurrent weekends followed by knockout stages, with players assigned to teams via auction, similar to cricket's Indian Premier League or The Hundred.

Organisers claim they will be choosing from a pool of "192 of the world's best male players", with teams also having to select at least two players from Tier Two Nations, as well as one Under-20 player.

Former RFU CEO Ian Ritchie will serve as chairman, and claims the new tournament will compliment the rugby calendar rather than disrupt it.

"World 12s is a natural evolution for rugby union," Ritchie said.

"We feel that this is a game for our changing, fast-paced world that can excite a global fan base in the way that we have seen with the IPL or most recently The Hundred in cricket.

"In bringing together the most exciting players under the stewardship of some of the brightest rugby minds with commercial backing, we are looking to propel rugby forward and lay a positive roadmap for how the game is perceived for future generations.

"Early and informal discussions with World Rugby, unions, clubs and player associations have been constructive, and in announcing today we can continue our consultative conversations and collaborations with the relevant stakeholders," Ritchie added.

The proposal has been backed by ex-New Zealand boss Hansen and former Springboks coach White.

"The idea of an international 12s tournament involving the world's best players alongside some of the most exciting developing talent in a short form, fast-paced version of the sport is extremely exciting for coaches, players and fans," Hansen said.

"I believe 12s will complement the existing calendar, attracting a new breed of fans from around the world," he added.

World 12s say a women's format will be played alongside the men's tournament starting in 2023, with no tournament possible in 2022 due to the World Cup taking place in New Zealand.

Despite the heavyweight names attached, the sport's global governing body World Rugby has responded to its launch by questioning how it will fit within the new global calendar which is currently being drawn up.

"We are aware of the proposed new World 12s competition," a World Rugby spokesperson said.

"While we welcome innovative thinking with the potential to advance the reach, attractiveness and growth of the sport, comprehensive consultation with the organisers is required to understand the viability of the concept, particularly in the context of ongoing global calendar discussions and the priority area of player welfare."

Unquestionably the biggest problem the World 12s faces is player release, with clubs and provinces in European leagues unlikely to allow their stars to take part during a time of year when they are either on holiday or in pre-season.

And the prospect of All Blacks, Wallabies or Springboks being involved are minimal because of the Rugby Championship being held at the same time.

"We were made aware of the project to create a new 12-a-side tournament on Monday," read a statement released by the Gallagher Premiership.

"We believe any proposed new competition will require extensive consultation. It can only be considered in the broader context of player welfare and the already congested global calendar."