Alessandro Dudech, the chief operating officer of Uniqlo UK, said Generation Z shoppers want clothes that they can wear both “at the office or on a night out”.

Shoppers under the age of 29 made up about 16% of sales in 2019, but this has more than doubled to 35% in 2023, Mr Dudech told the PA news agency.

The Japanese-owned brand has seen several products go viral on TikTok, especially its crossbody bag which has been dubbed a “Mary Poppins” accessory for its compact size but surprising spaciousness.

More recently, its bra tops, which have built-in bra cups, and the brand’s pleated wide-leg trousers have gained social media attention.

Mr Dudech says the company maximises social media-driven trends but is not actively chasing them.

“Clearly we are connecting more with younger customers,” he told PA.

“But I think it is also because what Gen Z value in clothing is changing – they are becoming more and more discerning about the quality that goes into their clothing, and they are looking for versatile pieces.”

Sales of women’s clothing ranges overtook men’s for the first time last year, he revealed.

Mr Dudech, who first join Uniqlo on its graduate programme on the shop floor in 2012, said that flagship stores in Europe were driving a large part of the company’s profits.

The Japanese retailer has the majority of its more than 1,000 stores in Asia, but four flagship European stores are ranked in the group’s top 10 globally.

It opened a new flagship on London’s Oxford Street on Thursday, which has features including “magic tills” which automatically scan items at self-checkouts, and an automated click-and-collect zone.

Its store in London’s Covent Garden, which opened last year, has a customised embroidery service and in-store repair service which can mend holes and replace buttons. It also has a Japanese tea room.

Mr Dudech said Uniqlo tailors its stores to the needs of the type of shoppers who visit, such as commuters on the move versus tourists who can spend more time.

He believes high street stores need to have a “reason of being” in the current environment where shoppers can easily go online instead, adding: “They need to be adding something to the experience.”

The brand’s parent company, Fast Retailing, invested in a technology called radio frequency identification (RFID) chips that are hidden in its clothes.

This tagging powers the self-checkout system and helps the company keep track of stock, as well as helping to reduce shoplifting.

Uniqlo plans to open 10 stores in Europe in 2024, with a further 15 in 2025 and 20 in 2026.

Sales across the UK and European business soared by more than a third to 1.3 billion euros (£1.1 billion) in the year to the end of August, according to its company accounts.