Former Wallabies star Israel Folau could represent Tonga at the next Rugby World Cup after changes to eligibility requirements opened the door for him to make the switch.

Axed by Rugby Australia in 2019 after homophobic social media posts, Folau has been out of international rugby union ever since.

That absence, combined with the fact both his parents are Tongan, could open the door for the cross-code star to join the ʻIkale Tahi in time for the 2023 Rugby World Cup in France.

Previously a player could not switch from one union to another if they had represented their nation's senior team, but that has now been scrapped.

Now, the player has to show "a close and credible link" to the country in question — if they, one of their parents or one of their grandparents were born there; or if they've lived there for five years in a row, or 10 years all up.

If that is established, the player can simply stand down from international rugby for three years before rejoining with the new national side.

Tongan head coach and former Wallaby Toutai Kefu told the ABC's Pacific Beat he spoke to Folau about making the move.

"I don't have a problem with that. There hasn't been any been restrictions from World Rugby's side," he said.

There have long been calls for rule changes particularly to allow Pasifika stars to play for countries of their parents or even their own birth, and Oceania Rugby president Richard Sapias said the vote could reshape rugby union in the southern hemisphere.

"For a country the size of Tonga, you imagine the amount of players they have overseas," he told Pacific Beat.

"There's a lot of talent out there and it gives them a wide range of opportunities to choose from."

Australia set to host 2027 Rugby World Cup

World Rugby also announced its "preferred candidates for upcoming World Cups, with Australia set to host the 2027 men's tournament.

The World Rugby Council met last night and announced it would work exclusively with Australia on a model. However the hosting rights will not be officially locked in until a vote in May next year.

Australia has not hosted the Rugby World Cup since 2003, when the Wallabies lost to Jonny Wilkinson's English side in the final, with 2015 the team's only other appearance in a final since then.

The Wallabies last lifted the Webb Ellis Cup in 1999, and Rugby Australia chairman Hamish McLennan said winning the hosting rights could help move the sport back towards its halcyon days.

"Throughout this process, we've held the genuine belief the time was right to bring the Rugby World Cup back to our shores."

England was announced as the "preferred candidate" to host the 2025 women's tournament.