Sales at its department stores have been hit by the World Cup

Ending a 140-year tradition of only having internal directors, the retailer said the move would bring a fresh perspective as it continues to develop.

The two external directors will join the five executive directors and five staff members elected to the board.

John Lewis also said that while its Waitrose supermarkets had enjoyed a World Cup boost, its department stores had suffered a fall in sales.

It said that last Saturday - which saw England play its first World Cup game against Paraguay - was the worst Saturday of the year at its 27 John Lewis stores, as people stayed at home to watch the match.

Yet not before they stocked up on food and drink, helping the Waitrose stores enjoy a 12.7% year-on-year jump in sales for the week to 10 June.

'Fresh challenges'

John Lewis remains the UK's largest example of worker co-ownership, with all 64,000 permanent staff being partners in the company.

Its chairman Sir Stuart Hampson said the firm's current success makes it "ever more alert to the continuous change within the markets we serve".

"The appointment of non-executive directors will bring external experience to our debates and introduce fresh challenges and stimulus as we adopt new initiatives and develop our existing formats," he said.