As the European club rugby season kicks off this weekend with the opening rounds of the Heineken Cup and the Amlin Challenge Cup, tournament organisers, the European Rugby Cup, have instructed all match officials in both competitions to be particularly vigilant in a number of key areas.

The key areas of focus, which are in line with those emphasised by the International Rugby Board during the recent Rugby World Cup, are the 'Big 5': dangerous tackles, the breakdown, scrum engagement, obstruction, and offside at rucks and from kicks.

The former Test referee Donal Courtney is in charge of the ERC and has had meetings on the matter with club coaches of the 44 clubs taking part in the Heineken Cup and Amlin Challenge Cup and with the referee managers of the Six Nations' countries.

Courtney said: "We've made sure that all match officials and club coaches are aware of the five key areas which we believe demand particular attention at the moment, and as organisers of Europe's leading club tournaments, we are expecting a consistency of approach from all match officials throughout the tournaments.

Dangerous tackles include the tip tackle, the breakdown includes sealing off, the scrum engagement includes care when scrums collapse, obstruction includes obstruction at line-outs and kick-offs, offside at rucks includes the position of them pillars at the side of the ruck and offside from kicks includes players moving forward at kicks downfield.

The ERC has also appointed citing commissioners for all Heineken Cup matches and all televised Amlin Challenge Shield matches.

Half-time at matches in both competitions will now be increased from 10 to 15 minutes - thus allowing more time for advertisements.