Why has Debenhams stumbled on the high street?

John Lewis has reported strong trading over Christmas, with like-for-like sales up 6.9% compared to a year earlier.

House of Fraser also reported solid Christmas sales, but Debenhams announced the resignation of its chief financial officer, Simon Herrick, just two days after it warned of a disappointing Christmas season.

Speaking to BBC Breakfast's Charlie Stayt and Louise Minchin, John Pal, a retail analyst at Manchester Business School, explains how the differing structures of John Lewis Partnership and Debenhams could be part of the reason for their varying fortunes on the high street.