World Rugby has approved an amendment to the game’s eligibility laws which will see players no longer permanently tied to one Test team and able to switch to play for another country, which could open the door for Mako and Billy Vunipola to play for Tonga in the future.

From January 1, 2022, players will be able to switch to play for a new union providing they have a birth right or relative born in that country, and also stand down from Test rugby for a period of 36 months. A player may only change union once, and each case will be subject to approval by the World Rugby Regulations Committee.

Both Vunipola brothers last played for England in March and, providing they did not play for England again, would not qualify to play for Tonga until March 2024. Saracens back Alex Lozowski is another high-profile name who could now switch to play for Italy, having not been capped by England since 2018.

The news comes as a major boost in particular for ‘tier two’ sides including Fiji, Samoa and Tonga, with players, in particular, who have previously represented New Zealand and Australia but are no longer playing for the All Blacks or Wallabies now able to switch allegiances.

Dan Leo, the former Samoa lock and head of Pacific Rugby Welfare who has extensively campaigned for World Rugby to review the eligibility laws, told Telegraph Sport that the decision was “a momentous occasion for all of rugby”.

“I think the sport has struggled to provide a true competitive balance at World Cups. There’s been a big divide between the haves and have-nots. It will be a game-changer for the Islands – Samoa, Tonga and Fiji are going to be massively revamped by this. It will make the next World Cup so exciting,” said Leo, revealing that Lima Sopoaga, the former All Blacks fly-half, and Bristol captain Steven Luatua had already contacted him about switching Test teams.

Leo added that stronger Pacific Island sides on the field could hopefully lead to greater investment opportunities for the teams off the field.

“We are not going to be coming to Twickenham for 70-point hidings any more. They are going to be top-drawer games,” Leo continued. “My hope is the money comes back to the Islands as well. That’s the key for me. We can’t just be a money-maker for other countries. Hopefully with better results comes better sponsorship and higher levels of interest.”

Tonga, by the next Rugby World Cup, could be bolstered by having star Bristol and former New Zealand full-back Charles Piutau in their side, along with a number of other talents including Ngani Laumape and Vaea Fifita. Former Australia back Israel Folau could also be part of Tonga’s squad if he returns to rugby union, having last played for Australia over three years ago.

Telegraph Sport additionally understands that the World Rugby chairman Bill Beaumont and also Joe Schmidt, World Rugby’s director of rugby and high performance, were key drivers behind the amendment, while Portugal and Spain also strongly pushed for the law change.

Players who could switch XV

*= can switch immediately from Jan 1st, 2022 having not played for previous Test side in 36 months

15 Charles Piutau (Tonga, from New Zealand)*

14 Israel Folau (Tonga, from Australia)*

13 Tevita Kuridrani (Fiji, from Australia)

12 Ngani Laumape (Tonga, from New Zealand)

11 Taqele Naiyaravoro (Fiji, from Australia)*

10 Alex Lozowski (Italy, from England)*

9 Morgan Parra (Portugal, from France)

1 Alec Hepburn (Australia, from England)*

2 Agustin Creevy (Italy, from Argentina)

3 Jeffery Toomaga-Allen (Samoa, from New Zealand)*

4 Vaea Fifita (Tonga, from New Zealand)

5 Steven Luatua (Samoa, from New Zealand)*

6 Don Armand (Zimbabwe, from England)*

7 Jordi Murphy (Spain, from Ireland)

8 Nathan Hughes (Fiji, from England)