Edinburgh could have a team in the league as early as next season, after a gap of nine years since Scottish teams last played in the competition when Glasgow Rangers and Murray Livingston finished first and second.
The Leeds franchise was given new impetus this week. Leeds City Council have freed the majority of a 50-acre site for pounds 11.3m to Caspian, who own Leeds United Football Club and plan to include a 14,000 seat indoor arena at the Elland Road redevelopment.
But it is the proposed franchise in Belfast which represents the most startling development of having a team sited off the mainland for the first time.
The League chief executive, Mike Smith, said: "As we've shown in recent years, our policy is to develop the game through the new arenas.
"There is a millennium project in Belfast in which we are very interested and we are in talks for the franchise in Edinburgh, which could be ready next season."
Travel costs would be a stumbling block, particularly for southern and Midland teams. Smith said: "At the moment, we are looking positively at all the options and the practicalities will follow later."Reuse content