Lee Scott, president and chief executive of US retail giant Wal-Mart has called for the UK government to investigate the growing dominance of Tesco in the grocery sector.

Scott, whose company also owns Asda in the UK, said: "As you get over 30% and higher I am sure that there is a point where government is compelled to intervene, particularly in the UK, where you have the planning laws that make it difficult to compete."

"At some point the government has to look at it," he added.

Exclusive research conducted for The Grocer by ACNielsen released this week revealed that Tesco's market share has increased by 0.7% since May to 30.7%.