The International Hockey Federation (FIH) has announced that the process to decide the teams who take part in the inaugural competition, a key element of their competition portfolio from 2018 onwards, has been opened.

The sport’s worldwide governing body has claimed "detailed eligibility" criteria has been sent out to Member Federations.

They have warned any interested nation must be able to demonstrate "evidence of financial sustainability", describing it as "critical" for those who are considering entering the competition.

"While details about marketing proposals for promoting the League and commercial strategies aimed at generating income will be required, evidence of financial sustainability will be critical," the FIH said in a statement.

"This will include detailed modelling, projecting budgets for both the participation in matches overseas as well as hosting matches in their homeland."

The performance history of the applicants will also be considered, the FIH confirmed, in order to "ensure the quality of the teams taking part is what is needed to provide a competitive league".

This may prevent smaller nations entering the event, raising concerns over whether they may be further alienated from the game’s elite.

The name of the league has not yet been decided, while the FIH are set to reveal the competing nations in June 2017.

insidethegames understands Great Britain, whose women’s team clinched the Olympic gold medal at Rio 2016, may be included in the league, despite them not being a member of the FIH.

A final decision on their participation has not yet been finalised, with the home nations separate members of the organisation.

The league, which is controversially replacing the Champions Trophy as well as the Hockey World League Semi-Finals and Final, will feature between seven and nine teams.

The men’s and women’s sides involved will play home and away against the other teams each year, with matches held in Southern and Northern Hemisphere rounds to ensure the best possible weather conditions.

Following the completion of the league phase, the top four countries will compete in a standalone grand final to crown the overall winner.

"This is the first step towards the implementation of our game-changing new event portfolio," FIH acting chief executive David Luckes, a former England goalkeeper and an important figure in London's successful bid for the 2012 Olympic and Paralympic Games, said.

"It’s been designed to provide a regular calendar of must‐see events played in packed stadia across the world throughout the year and will therefore completely change the landscape of international hockey.

"This is the start of an extensive consultation process which will ensure the quality and sustainability of these leagues.

"Over the coming months we will be helping all of these nations with the application process and look forward to announcing the teams as the next step in the summer of 2017."

The new competition portfolio has been established in response to hockey nearly being cut from the Olympic Games programme in 2013.