Tesco has begun legal proceedings against the Guardian and its editor, Alan Rusbridger, over a series of articles about its tax affairs, the paper confirmed today.

Britain’s biggest retailer is suing for libel – and malicious falsehood – over the claims, which were published both in the paper and in a podcast.

The Guardian Media Group has itself become embroiled in the tax avoidance debate after it emerged the publisher had incorporated a company in the Cayman Islands for its purchase of Emap’s B2B magazines division.