Tesco’s incoming UK chief executive Richard Brasher has dismissed suggestions that its ramped-up loyalty programme is inflating UK sales.

“Some of the numbers that have been quoted are completely disproportionate to reality,” Brasher told the Financial Times.

The retailer doubled rewards to customers using its Clubcard scheme about 18 months ago and will allow shoppers to double vouchers in-store this Christmas.

Unlike rivals, Tesco counts voucher sales as cash sales and makes an accounting adjustment to statutory results.

Evolution analyst Dave McCarthy has estimated there is an extra £100m of Clubcard vouchers in circulation this year and £200m more than compared with two years ago.

On sales of £5bn that could mean a lift in sales from stores open for two years of 2% over Christmas.

Brasher said Clubcard was “a very important part of what we do… We are very comfortable in the way we account for it.”