Wallabies great George Smith’s Rio Olympic dream may be dashed after world body IRB tightened their rules for nationality switch.

The goal posts have suddenly changed for Wallabies great George Smith in his bid to represent Tonga at the Rio Olympic Rugby Sevens.

And frustrated Australian duo Brock James and Blair Connor’s hopes of running out for France at the 2015 Rugby World Cup may have been dashed barely a week after being named in the country’s preliminary squad.

World body the International Rugby Board (IRB) have announced tightened rules to close a “loophole” for players to switch nationalities – and it doesn’t auger well for the Aussie trio.

Players looking to represent another country will have to play at least half of the eight-round World Sevens series starting in October for their adopted country if they wish to switch their allegiances.

The IRB said players who go down this path must also contest the 2016 Rio Games where rugby sevens is making its debut.

To boot, the IRB’s new edict states players who fail in their application to switch allegiances will be barred from reverting to their original team.

The IRB’s initial eligibility rules stated a player could represent a country provided they have the correct passport and had not been capped by another team for 18 months.

And under the previous rules, an appearance in just one Olympic sevens qualification event could lead to a player being selected for that nation’s 15-a-side team.

It seems to have shut the door on 110-Test Wallabies flanker Smith who has just begun a two-year contract with French club Lyon and is unlikely to be released from his lucrative deal to play Sevens.

It is also bad news for James – one of the highest paid Australians in world rugby – and Connor who had hoped to run out for France at the World Cup after being named in an initial 74-strong squad last week.

Sydney-raised five-eighth James (Clermont-Auvergne) and ex-Queensland Reds flyer Connor (Union Bordeaux) are both starring in Europe and their French Top 14 sides are unlikely to let them skip club duty and run out in the World Sevens series in order to earn a Cup nod.

James, 32, has become one of European rugby’s biggest names since moving overseas in 2006 but is relatively unknown in his home country.

He has helped Clermont-Auvergne claim the European Challenge Cup in 2007, the Top 14 title in 2010, and was part of their Heineken Cup final loss to Matt Giteau’s Toulon in 2013.

Another affected by the tightened IRB rules was current European Player of the Year Steffon Armitage of England who had also been named in the French squad.

The IRB had indicated that they were ready to prevent “exploitation” of their regulations in a bid to prevent a flood of players switching allegiances in order to compete at the Rio Games.

“These rulings of the IRB Regulations Committee will further assist our unions with their preparation and underscores our commitment to ensure a successful and spectacular Olympic Games debut at Rio 2016 and beyond,” said IRB chairman Bernard Lapasset.