Chief executive Arthur Ryan, who founded the retailer in 1969 and is now in his early 70s, will become chairman.

He will be replaced by chief operating officer Paul Marchant, who joined Primark in January after working for high street chains including Debenhams, New Look and Topman.

Mr Ryan oversaw the growth of the chain from the opening of its first store in Dublin, where it is called Penneys, 40 years ago.

It has since expanded to 191 stores across the UK and overseas to Spain, Portugal, the Netherlands and Germany.