They will still be called French fries, but from now on McDonald's is to use only British potatoes for all of the chips it sells in UK branches.

The chain has pledged that for the first time, all McDonald's UK French fries will be made from British potatoes.

The move will make the fast food chain one of the largest buyers of British potatoes and will see McDonald's UK increase its investment by around £9 million on 2013/14 investment levels. It will be spending £79 million a year on British potatoes.

The move to British potatoes is part of an initiative by the chain, which has just over 1,250 UK restaurants serving more than three million customers a day, called "farm forward", to support British and Irish farming.

Connor McVeigh, UK supply chain director at McDonald's, said: "Our customers like us to source locally wherever possible, and so we're pleased to announce that from September, the only potatoes we'll use for our famous fries will be British.

"A succession of wet harvests has caused the British potato sector great uncertainty in recent years, and so I hope our long-term commitment to only source from this country will give farmers the confidence to innovate and invest for the future."