Tesco has hired heavyweight libel lawyers Carter Ruck and barrister Adrienne Page QC to fight its groundbreaking tax libel case against The Guardian over a series of stories the paper published about the supermarkets’s tax arrangements.

The action is believed to be the first ever libel suit brought over tax avoidance allegations. Libel experts believe the case opens up new areas of libel law.

The Guardian has left its in-house legal team to look at the issue at this stage.

Tesco is disputing articles which claimed it had avoided large sums in tax through an offshore scheme. It disputes both the sums avoided and the type of tax it avoided. It said the details of the transactions have or would be included in its tax returns.

The paper says it put the allegations to the supermarket group, and that Tesco is trying to shut down debate on an important subject of public interest.

James Bullock, tax litigation partner at McGrigors, said the fact that a large corporate was pursuing a libel action over tax avoidance demonstrated how important the issue had become to companies.

‘Tax avoidance is manifestly not a crime ­ nor is it necessarily wrong in law. But HM Revenue & Customs has been very successful in making it a reputational issue for corporates in particular, with the effect that it has almost become an issue of corporate and social responsibility,’ he said.