Tesco’s major shareholder Harris Associates has sold two thirds of its stake in the business and blasted the supermarket for having no clear strategy.

Harris Associates international equity division chief investment officer David Herro told The Sunday Telegraph that he had reduced the investment from 3% to 1% in the last month.

Herro has asked that new chief executive Dave Lewis, who starts today, sets you a clear and coherent strategy quickly.

He told The Sunday Telegraph: “If this thing is a turnaround story, we want to stay involved, but we need to hear a plan that makes sense.”

Herro wants Tesco to differentiate from rivals by improving customer service rather than simply relying on price competition.

News of Harris Associates comes after Tesco revealed its second profit warning in two months on Friday and brought forward Lewis’ start date.

Lewis was due to start the new role in October, but following the latest profit warning he has been parachuted in early.

Tesco has reduced its dividend by 75% in order to provide Lewis with more cash to make changes at the struggling retailer.