Leading UK retailer Tesco has accused sector rival Sainsbury’s of foul play.

Tesco accused Sainsbury’s of sending money-off vouchers to households in areas where competition between the two supermarkets is fierce, and retaliated by saying it would allow customers to redeem the Sainsbury’s vouchers in its own stores.

“This is the latest spat where more expensive supermarkets try to lure our customers away,” Tesco marketing director Tim Mason is quoted as saying by the Independent.

Sainsbury’s attributed Tesco’s reaction to what it claims is a normal voucher mailshot, to deepening concern over the apparent success of the new Nectar loyalty card. Sainsbury’s secured the right to be the only grocer in the card scheme, which brings together Debenhams, BP and Barclaycard and hopes to have signed up half of UK households by the end of year one.

Tesco said its policy of accepting vouchers from other companies, which began on Saturday, also applied to fourth-largest supermarket group Safeway. However, a spokesman told the Independent the smaller chain said it was confused by this move, as it had not sent out money-off vouchers recently.