Europe's top 24 clubs will learn their Heineken Cup opposition at todays draw in Twickenham (1200 BST).
The first-seeded sides from each of the six nations - Biarritz, Treviso, Sale, Ulster, Cardiff Blues and Edinburgh - will be drawn in separate pools.
Although Munster won last season's competition, Ulster gain the top Irish seeding as they won the Celtic League.
England: Gloucester Rugby, Leicester Tigers, London Irish, London Wasps, Northampton Saints, Sale Sharks
France: Agen, Biarritz Olympique, Bourgoin, Perpignan, Stade Francais Paris, Toulouse, Castres Olympique
Ireland: Leinster, Munster, Ulster
Italy: Benetton Treviso, Rugby Calvisano, Overmach Parma
Scotland: Edinburgh Gunners, Border Reivers
Wales: Cardiff Blues, Llanelli Scarlets, Ospreys
The 24 teams from six countries will be split into eight categories and drawn from the ERC draw drum by ERC Chairman, Jean-Pierre Lux, and RFU Tournament Director, Terry Burwell.
Each time a team is drawn, a ball representing the Pool they will compete in will be drawn from the ERC draw bag by ERC Chief Executive, Derek McGrath.
The aim is to ensure that there are four teams in each Pool and that there is no more than one team from each country in a Pool, with the exception of France who have seven teams and so will have two of their clubs in one of the Pools. France earned an additional place by being the most successful nation out of England, Italy and France in the 2005/6 tournament.
The six top seeded teams from each nation - Biarritz Olympique Pays Basque, Sale Sharks, Ulster Rugby, Benetton Treviso, Cardiff Blues and Edinburgh Gunners will be drawn out of the ERC draw drum and assigned a Pool number. That process will give the leading team for each pool.
The five French teams ranked 2-6 will be next to be drawn from the drum. They are Toulouse, Stade Francais Paris, Perpignan, Agen and Bourgoin.
Only five balls (the Pool containing Biarritz will be excluded) will go into the draw bag to determine their Pool placements.
After the five French teams come the remaining five English clubs Leicester Tigers, London Irish, London Wasps, Gloucester Rugby and Northampton Saints who will be drawn out and allocated their Pools. The Pool containing Sale Sharks will be excluded from the draw bag.
PHASES 4, 5 AND 6
The two remaining Irish teams Leinster and the 2006 Heineken Cup champions Munster will be placed in Pools (Ulster Rugbys Pool excluded from the draw), followed by Italian sides Ghial Rugby Calvisano and Overmach Rugby Parma (Benetton Trevisos Pool excluded from the draw) and then the remaining two Welsh regions, Llanelli Scarlets and the Ospreys (Cardiff Blues Pool excluded).
PHASES 7 AND 8
The remaining Scottish representative, Border Reivers, will then be allocated a Pool (excluding Edinburgh Gunners Pool) and then the seventh and final French club Castres Olympique will be placed in the final vacant Pool position.