The tax libel row between Tesco and the Guardian has seen Carolyn McCall, Guardian Media Group chief executive, quit her non-executive roll at the supermarket.

In a stock exchange announcement Tesco said McCall had decided to step down from the supermarket's board because of a 'conflict of interest'.

Tesco chairman David Reid said he had accepted McCall's resignation 'with regret' as she had made 'a strong contribution to the success of the business'.

Earlier in the week Tesco said it had no problems with McCall staying on the board as a non-executive as she had absented herself from any discussions that could have left her conflicted.

Tesco issued a High Court writ against the Guardian last week over a series of stories the paper published about the retailer’s tax arrangements.

Tesco is disputing the 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 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.

Further reading:

Read the stock exchange announcement here

Tesco backs Guardian executive on its board