npower will be responsible for providing all M&S's retail outlets and offices with electricity.
The deal, which will see the electricity generated from green sources such as wind farms and hydroelectric plants, is part of M&S's Plan A, which will see the retailer become carbon neutral by reducing its energy usage and using offsetting as a last resort.
Richard Gillies, director of Plan A at M&S, said: "Not only does it significantly move us towards our goal of using 100 per cent renewable electricity across our stores and offices, it also strengthens our market-leading commitment to encouraging small third-party generators."
In related news, M&S is attempting to renegotiate supply contracts to reduce the impact of the weakening pound on its business.
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