It will also be keeping up its BOGOF activity throughout the launch period and is expected to redirect at least 30% of promotional spend to the launch.
When Nectar was announced in June, its backers claimed it would reach 50% of UK households, boosting loyalty and providing access to shared resources.
City opinion about the likely success of the scheme was mixed, with some analysts sceptical about its long-term benefits and concerned its backers have underestimated the challenges. One analyst said: "Nectar may well have a massive short-term impact as Sainsbury is pumping a huge amount of cash into the launch. But it's not a new card, so its attraction to new customers will be limited.
However, Cheuvreux analyst Mike Dennis said Nectar could provide a real boost to sales if customers bought into the idea of rapid points accumulation from multiple outlets offering big returns, more quickly. "Nectar lets Sainsbury communicate more effectively with customers at home," added Dennis.
n Air Miles pre-empted the Nectar launch this week by unveiling a major direct mail and TV ad campaign to plug new partners BT and House of Fraser and a host of new offers.