French duo Biarritz and Toulouse are already through from Pools 2 and 5 respectively, but with one round of matches there is still all to play for in the other four pools.

For Saints one thing is simple - win at Thomond Park tomorrow night and they will secure a quarter final spot. It is if they don't win that things become complicated. Even if Munster got two losing bonus points in this scenario Saints would still top the pool thanks to the head-to-head record between the teams.

A draw, or two bonus points from losing by seven points or less and scoring four or more tries, would put Saints on 20 points, meaning that London Irish would need a bonus point win over Leinster to be in with a chance of qualifying. They would also need to have bettered the Saints' number of tries; at present the Saints have scored 16 and Irish 15.

The focus is on the battle between the Saints and London Irish for a runners-up spot. This is because it is assumed that the other best runners-up spot will come from Pool 3, where Leicester have 17 points and the Ospreys and Clermont Auvergne both have 16. The Tigers finish their campaign at the Liberty Stadium on Saturday afternoon, Clermont travel to Viadana. Should Leicester and the Ospreys draw, however, and the Italians pull off a massive upset, then the Tigers would win the pool and the other two would be out of the competition.

Pool 4 is also intriguingly poised. Stade Francais are currently four points ahead of Ulster, but face a daunting trip to Murrayfield to face Edinburgh. Meanwhile the Irish province round their pool matches out at the Rec, where they face a Bath outfit that has nothing to play for. Should Stade lose and Ulster win with a bonus point, the latter will qualify for the quarter finals and the former will almost certainly be out.

The other two pools are more clear-cut. Gloucester, currently in second place in Pool 2, can only qualify for the Amlin Challenge Cup quarter finals should they get a bonus point win in Newport and the second placed teams in Pools 4, 5 and 6 all lose.

In Pool 5, Sale and Cardiff are battling it out for second place. Both are tied on 13 points and have an outside chance of qualifying for the quarter finals, should the Saints and London Irish both lose. But Sale are hosting Toulouse, who need a five-point win to all-but-guarantee a home quarter final, while the Blues are travelling to Harlequins, who have nothing to play for.

All bar three of the 12 Round 6 matches will be shown live on Sky Sports and Sky Sports Interactive. Visit www.skysports.com/rugbyunion for all the details.

Saints supporters - and those exiled from Munster into the East Midlands of course! - can watch all the action from Thomond Park in the Rodber Suite. The bar opens at 6pm with the game kicking off at 8pm (over-14s only).