Morrisons is claiming the cheapest milk on the market as price war intensifies.

The move comes after Tesco on Monday (3 March) reduced the cost of 4 pints of milk to £1 as part of its £200m investment in offering “lower, more stable” pricing to customers. Sainsbury’s quickly followed suit, while the Co-op on Wednesday (5 March) reduced the cost of a pint to 45p and 2 pints to 85p as part of a new strategy that will see it focus on price, convenience and own-label products.

Waitrose yesterday said members of its myWaitrose loyalty scheme would also be able to buy 4 pints for £1, although regular shoppers would still be charged £1.39. The supermarket says that more than two-thirds (68 per cent) of customers use its loyalty programme.

Asda already sells 4 pints of milk for £1.

The main supermarkets are all under pressure to cut their prices as shoppers increasingly use discount rivals such as Aldi and Lidl. Both experienced double-digit growth over Christmas, far outpacing the big four.

However, the focus on milk has caused concern among dairy farmers worried that the price war could affect the amount they are paid for milk. Morrisons says its price cut will be funded entirely by the supermarket, while Tesco took out print ads to assuage farmers’ concerns, alongside a campaign promoting its new price.

Morrisons category director Steve Mosey says: “We’re looking after families while still looking after farmers.”