Tesco and Sainsbury are reported to be at loggerheads following accusations of customer poaching.

According to this morning’s press Tesco has accused Sainsbury of sending vouchers to households in key areas where competition is fierce.

Tesco’s response to the mail shots was to announce that it would accept Sainsbury's coupons at its stores.

Marketing director at Tesco, Tim Mason, told The Independent that this was “the latest spat where more expensive supermarkets try to lure our customers away”. He said Tesco would be flexible and “accept the vouchers they're sending to our shoppers”.

Earlier this week Tesco said its policy of accepting vouchers from other companies also applied to Safeway, which had supposedly sent money-off vouchers by e-mail to Tesco customers. Safeway denied this and said “it was confused by the move”.

Meanwhile, Sainsbury has insisted that the mail shots were sent as a matter of course throughout the year. It added that its launch of the Nectar loyalty card, in partnership with Debenhams, BP and Barclaycard, targeting 50% of UK households could have sparked the situation.

A spokeswoman for Sainsbury said: “We think this [response] is a pretty desperate move by Tesco.

“It clearly shows how worried they are about the impact of Nectar and the overwhelming customer response we have had since it was launched two weeks ago.”