Ocado has rolled out the Low Price Promise nationwide – pledging to beat Tesco on the cost of all comparable shopping baskets.

The extension of the price-matching scheme for branded groceries already in place with Tesco was trialled in recent weeks, starting in the Manchester area and then in the West Country and Oxfordshire.

The Low Price Promise works by totting up the cost of the groceries customers have bought – including Essential Waitrose and Ocado own-label products – before comparing the total with what they would have paid for the same basket at Tesco.

If the total comes out cheaper at Tesco, Ocado has promised to give customers a money-off voucher for the difference, plus a penny. The comparison will take into account any promotions Tesco is running.

“We’ve matched Tesco’s prices on branded goods for many years and now with our Low Price Promise we’re going one step further by giving customers across the country a money-off voucher if we don’t beat Tesco’s prices,” said Ocado co-founder Jason Gissing.

“As the name says, this is a promise to our customers. Now we won’t just match Tesco prices. We’ll beat them.”