The Pool 4 meeting of the two former champions will guarantee a sell-out at Ravenhill, while on the same night the qualification picture in Pools 2 and 5 is also likely to become clearer when Racing Metro 92 take on joint pool leaders, Edinburgh Rugby, at Stade Yves du Manoir in Paris, and when Ospreys go up against Benetton Treviso at the Liberty Stadium.

The dates and kick-off times for Rounds 5 and 6 of the Heineken Cup were announced today (Wednesday, 21 December 2011) by ERC, and Munster Rugby - the only club with four wins in the pool stage to date - will continue their push for a coveted place in the last eight when they host Castres Olympique at Thomond Park on Saturday, 14 January 2012 before rounding off their Pool 1 campaign a week later against Northampton Saints at stadium:mk in Milton Keynes.

Cardiff Blues will travel to play London Irish on Saturday 14th January kick off 3.40pm at Reading's Madjeski Stadium and the following weekend will host Racing Metro Paris 92 on Sunday 22nd January kick off 3.15pm at Cardiff City Stadium.

Meanwhile, reigning champions Leinster Rugby who are unbeaten in Pool 3, travel to Firhill on Sunday, 15 January where they meet a resurgent Glasgow Warriors, while in Round 6 they will look to reach the knockout stages once again when they host Montpellier at the RDS on Saturday, 21 January.

Following Harlequins' outstanding Round 4 victory over Toulouse at Le Stadium, the outcome of Pool 6 remains on a knife-edge and the one definite place in the last eight will be determined on Friday, 20 January next when Harlequins take on Connacht Rugby at the Sportsground in Galway and when four-time champions, Toulouse, travel to Kingsholm for a meeting with Gloucester Rugby.

In Round 6, matches in the same pool will kick off at the same time. A full schedule of live television coverage for Rounds 5 and 6 will be announced at a later date.

FIXTURES
(All kick-offs are local time)
ROUND 5
FRIDAY, 13 JANUARY 2012
Pool 2 Racing Metro 92 v Edinburgh Rugby 21.00
Pool 4 Ulster Rugby v Leicester Tigers 20.00
Pool 5 Ospreys v Benetton Treviso 20.00

SATURDAY, 14 JANUARY 2012
Pool 1 Scarlets v Northampton Saints 13.30
Pool 3 Montpellier v Bath Rugby 14.00
Pool 4 Aironi Rugby v ASM Clermont Auvergne 14.30 (Stadio Brianteo, Monza)
Pool 1 Munster Rugby v Castres Olympique 15.40
Pool 2 London Irish v Cardiff Blues 15.40
Pool 6 Toulouse v Connacht Rugby 16.40
Pool 6 Harlequins v Gloucester Rugby 18.00

SUNDAY, 15 JANUARY 2012
Pool 3 Glasgow Warriors v Leinster Rugby 12.45
Pool 5 Saracens v Biarritz Olympique 15.00

ROUND 6
FRIDAY, 20 JANUARY 2012
Pool 6 Connacht Rugby v Harlequins 20.00
Pool 6 Gloucester Rugby v Toulouse 20.00

SATURDAY, 21 JANUARY 2012
Pool 3 Bath Rugby v Glasgow Warriors 13.30
Pool 3 Leinster Rugby v Montpellier 13.30
Pool 4 Leicester Tigers v Aironi Rugby 15.40
Pool 4 ASM Clermont Auvergne v Ulster Rugby 16.40
Pool 1 Northampton Saints v Munster Rugby 18.00 (stadium:mk)
Pool 1 Castres Olympique v Scarlets 19.00

SUNDAY, 22 JANUARY 2012
Pool 5 Benetton Treviso v Saracens 14.00
Pool 5 Biarritz Olympique v Ospreys 14.00
Pool 2 Cardiff Blues v Racing Metro 92 15.15
Pool 2 Edinburgh Rugby v London Irish 15.15