The Co-operative Group chairman has publicly backed chief executive Peter Marks amid claims of a boardroom bust up.

According to the Daily Mail, chairman Len Wardle interrupted his holiday to pledge support for Marks in the wake of damaging leaks about the performance of the Somerfield stores it bought in a £1.5bn deal.

The leaks were revealed exclusively in Retail Week on Friday.

It was also claimed the performance caused internal concern that changes in pricing and ranges alienated some Somerfield customers. The Co-op however said there are no problems integrating Somerfield and it disputes speculation that directors have concerns about Marks.

Wardle said: “The board of the Co-operative Group is united in its commitment to the continuing success of the business under Peter Marks’ leadership both commercially and in delivering its co-operative values.

“The Co-operative brand has never been stronger and more relevant than it is today, as was underlined by the record group results announced last month. We are getting on with running the business for our millions of members and customers.”

Retail Week revealed that the business is trading £33m below budget for the first two months of its financial year, with sales at those stores converted from Somerfield to Co-op down 14.1% in the most recent month.