European Cup Round-up: In the spat for outright supremacy in the six pools this fortnight sees several of the main protagonists go head to head. From an Irish perspective that is very much the case with Munster in Pool Four as they travel to the Stade Pierre Antoine for tonight's game against Castres Olympique.

It'll be the seventh meeting of these sides since the inauguration of the European Cup and the Irish province lead 4-2.

If Alan Gaffney's men can sneak a victory, and it's a very tough ask, they would be in the box seat in terms of qualification as they welcome the French side to Thomond Park the following week.

The duel between Wasps and Leicester (Pool One) with the first clash down for the Causeway stadium on Sunday promises to be a titanic tussle. A draw in the Zurich Premiership at the same venue underlines that the two games - Wasps head for Welford Road the following week - hang on a knife-edge. This pool, with Biarritz firmly in contention, could come down to a snatched bonus point or two.

It is a similar scenario in Pool Three where the two leading teams, last year's beaten finalists Toulouse and Northampton, clash over the next two weekends. The French side are in England this week and know a victory will all but secure a place in the knock-out stages.

Northampton must contend with the strife within, the sacking of coach Alan Solomons and the election of a new captain in Steve Thompson coupled with rank form in the Premiership to maintain their European impetus.

Leinster, in Pool Two, face a potentially tricky fortnight. Bourgoin's home defeat to Benetton Treviso constituted the shock of the tournament to date but they have recovered in the French championship since then. This weekend's other game in that pool which sees Bath travel to the Italian side will be crucial to the final outcome.

Ulster are fighting a rearguard action and the last place a team would want to go is to Stade Jean Bouin in Paris against the tournament's form team in Stade Francais. Ulster will be heartened by the fact their opponents are without several first-choice players.

There are very few teams who don't have a chance to turn around a bad start, with possibly Calvisano, Edinburgh and Cardiff lacking the quality in depth to do so. The next fortnight will shape several pools and nudge a handful of teams closer to the knock-out stages.