South Africa are on course to join the Six Nations after the next World Cup, in a move which will radically alter the international rugby landscape.

Sportsmail has learned that negotiations have been going on behind the scenes for some time and there is now a sense of inevitability that the Springboks will take their place in Europe's annual Test tournament in 2024. One source told this newspaper: 'Things are falling nicely into place.'

It is understood that the plan in principle would involve expanding the championship to a seven-team event - rather than South Africa's entry coming at the expense of struggling Italy. That would create pressure on an already congested calendar, but the rewards are regarded as too enticing to ignore.

South Africa are on course to join the Six Nations after the next World Cup

The Boks won the World Cup last November, beating England 32-12 in Yokohama. Adding such a powerful nation to the tournament would be a stunning coup for the northern unions and although the time frame is not finalised, the indications are that the change would take place in 2024.

There will be many profound repercussions. South Africa play in the southern hemisphere's Rugby Championship, along with Australia, New Zealand and Argentina. Their departure would leave a gaping hole, but it may allow for the integration of Japan, whose exploits at their home World Cup have led to demands for them to be accommodated in one of the two regular international competitions.

In recent months, there has been speculation linking Japan and Fiji with entry into the Six Nations, but Sportsmail sources claim this is unlikely.

The Boks won the World Cup last November, beating England 32-12 in Yokohama

South Africa are believed to be working on an equity injection which would give additional credibility to their arrival at Europe's top table, and complement the on-field kudos of being the holders of the Webb Ellis Cup. Joining an expanded Six Nations would allow them to align with countries far closer to their own time zone.

It would also increase the value of the Six Nations' television rights, both in Europe and their homeland, with kick-off times far more attractive to a domestic audience. With private equity eager to move rugby to satellite television, the arrival of the Springboks would give them an exciting new product to market.

The Rugby Championship TV rights in contrast are propped up by New Zealand, with interest in the tournament dwindling in Australia and South Africa.

Rugby has always been divided on hemisphere lines, but this has condemned the Springboks to gruelling travel demands while taking part in the Rugby Championship, which means players are left to cope with jet-lag. In contrast, flights to Europe would entail no more than a two-hour body-clock adjustment.

South African players have often voiced their desire to be involved in the north's blue-riband event. Many exiles from the country are employed by clubs in the European leagues and London in particular has a vast South African community.

South Africa are believed to be working on an equity injection which would give additional credibility to their arrival at the tournament

There has been an increasing shift in the global balance of power along economic lines, with the southern unions scrambling to prevent an exodus of their leading players to France and England. New Zealand have preferred to allow their stars to enjoy lucrative stints in Japan, which would make integration with the Far East nation a logical step.

In contrast, South Africa already have two provincial teams in the Pro14 league, along with teams from Ireland, Wales, Scotland and Italy, and they have had designs on greater ties with Europe for some time.

On Friday, the Six Nations announced details to bundle together commercial arrangements and media rights for the men's and women's championships, autumn Tests and other senior and Under 20 games.

Negotiations over new broadcast deals will now begin in earnest. They may soon become more attractive with South Africa on board.