Rumours are circulating that Sainsbury's chairman Sir Philip Hampton is planning to join Royal Mail Group, replacing chairman Allan Leighton when his current contract at the postal company is concluded in March next year.

Leighton, the former Asda boss, is battling to carry through widespread reforms at Royal Mail in order to bring postal services in line with the 21st century but has come under fire for his continued programme of Post Office closures in rural areas.

The Department of Trade and Industry refused to comment on whether Leighton would be leaving Royal Mail or if Sir Philip would in fact be his successor. "Allan Leighton's contract ends in March 2008 but his intentions after that are a question for him," said a spokesman for the Department of Trade and Industry.

Sir Philip joined Sainsbury's in July 2004 after leaving his role of finance director at Lloyds TSB Group.