European champions Leinster will launch the defence of their Heineken Cup title in a group with London Irish, the Scarlets and Brive.

The draw for the pool stages of the 15th Heineken Cup was made in Paris today and it has thrown up some intriguing clashes.

Magners League champions Munster will clash with French champions Perpignan in Pool One, which also features a return to Heineken Cup rugby for Northampton.

Last year's beaten finalists Leicester have again been drawn to face the Ospreys while Top 14 runners-up Clermont Auvergne and Italian side Viadana complete Pool Three.

But arguably the toughest group of all is Pool Five, which features French giants Toulouse, Heineken Cup semi-finalsts Cardiff Blues, Harlequins and Sale.

Jean Pierre Lux, chairman of European Rugby Cup, said: "All the pools look balanced apart from Pool Five - that was always going to be the case because of the second English team."

The Guinness Premiership has provided seven teams for the 2009-2010 Heineken Cup including two of the six top seeds in Leicester and Bath, who are in Pool Four with Stade Francais, Ulster and Edinburgh.

Biarritz-bound full-back Iain Balshaw will lock horns with his former employees at Gloucester plus the Newport Gwent Dragons and Glasgow in Pool Two.

Sale Sharks director of rugby Kingsley Jones admitted Pool Five is "a very difficult looking group".

Toulouse have won the title three times while Cardiff Blues won the EDF Energy Cup last season and only missed out on a place in the Heineken Cup final after losing a penalty shoot-out to Leicester.

Harlequins beat Stade Francais home and away last season and pushed eventual champions Leinster to the wire in a gripping quarter-final tie.

Jones said: "I can't see any side winning all their games.

"Cardiff were very unlucky last season to go out the way they did and Quins put up a great fight against Leinster.

"Toulouse are former winners of the Heineken Cup and will be looking to improve on their form in the competition over the past couple of years.

"Winning our home games will be a priority and we will need to pick something up on our travels too."

The 2010 Heineken Cup final will be staged at the Stade de France in Paris and organisers revealed more than 30,000 tickets had been already been sold for the match before the draw took place.

Around 18,000 tickets have been sold in France, with more than 12,000 purchased in the UK and Ireland.

The final in Paris is scheduled for May 22, 2010. Scotland loose-forward Ally Hogg is confident Edinburgh can continue their progress and qualify from what is a tough pool featuring Stade Francais, Bath and Ulster.

Hogg said: "I think it is a really good draw for Edinburgh. We know it will be tough, but we've got a good chance and everyone will be looking forward to the challenge.

"I've never played Stade before, so that should be interesting, especially with Simon Taylor and Hugo Southwell there.

"We beat Bath in a warm-up match last season, although they will be very difficult to beat and we know Ulster really well from our meetings in the Magners League."

Pool One:
Munster
Perpignan
Northampton
Treviso

Pool Two:
Biarritz
Gloucester
Newport Gwent Dragons
Glasgow

Pool Three:
Leicester
Ospreys
Clermont Auvergne
Viadana

Pool Four:
Bath
Stade Francais
Ulster
Edinburgh

Pool Five:
Toulouse
Cardiff Blues
Sale
Harlequins

Pool Six:
Leinster
London Irish
Scarlets
Brive