The John Lewis Partnership has announced that chairman Sir Charlie Mayfield is to step down in 2020.

The group, which also owns Waitrose, has begun the search for a successor and a new chairman will be announced in the second half of 2019.

Sir Charlie was the partnership's fifth chairman in its near 100-year history.

He said: "Although my departure is still a considerable way off, the appointment of my successor is a key responsibility. It is for this reason I have decided to lay out the timetable now to enable an open and thorough process to select the next chairman of the partnership."

The process for selecting a new chairman will be overseen by the company's nominations committee, comprising two elected directors, two independent non-executive directors and the chairman.

The committee is chaired by Keith Williams, the deputy chairman, and supported by independent recruitment consultants who will consider internal and external candidates.