While the Tories are in freefall, one former first couple are bucking the trend. Samantha Cameron, the designer and founder of the fashion brand Cefinn and wife of the former prime minister David Cameron, is about to open her first bricks-and-mortar store. The Belgravia boutique puts her back in the public eye, just as the role of foreign secretary has returned her husband to the frontline of politics.

Cefinn steers a course between garden-party nostalgia and modern life. Its sleek long floral dresses are aimed at a well-to-do customer who has taken half a day off work to be at a school sports day but needs to be back at the office to lead a meeting by 2pm.

The Elizabeth Street store in central London is a significant marker for Cefinn, which expanded its customer base by 23% last year. But there is a measure of irony in the post-Brexit trading conditions which Cefinn, along with many other small businesses, continues to battle with. Cameron, who in 2021 told BBC Radio 4’s Woman’s Hour that Brexit had made business survival “challenging and difficult”, says that “supply chain disruption continues to cause problems. There have been many moments when we have had to adapt and pivot to survive. This is not an easy time for many of our customers, and inflation has really impacted us as a business.

“Having a store allows us to meet our customers, to hear their feedback, to see what the collection looks like on different body shapes and sizes and different colourings. It is a small space, so it is intimate and friendly, with big changing rooms and great lighting so that hopefully it feels like a positive experience.”

Cameron took a pattern-cutting course during her husband’s second term in office and launched Cefinn just three months after his resignation in 2016. As a result, Cefinn is inextricably linked with her much-discussed Downing Street wardrobe. But Cameron insists Cefinn is “not just about me”. The name is an amalgam of her children’s names. “It is not named after me, which is something I felt strongly about. It is about all the women who work here with me, women who work really hard as well as having busy diaries outside work.”

Cameron said when she launched Cefinn that after the Downing Street years: “It’s Dave’s turn to support me.” She says now that “he’s always been very supportive, actually – I’ve always worked and it’s always been relatively even. Things are simpler now, because I don’t have any informal or formal commitments in his [foreign secretary] role, and our children are older. One has left for uni, so it’s just two teenagers at home and they are quite independent.”

She says being in Downing Street changed her own style and helped shape the brand. “I was a much more minimal dresser at the beginning, but I was lucky to get to wear lots of fabulous British designers like Erdem, Christopher Kane and Roksanda, and that introduced me to the power of colour and of print.” These days her style ranges from “days when I want to wear a simple black leather skirt and cream jumper, and days when I want to wear a really pretty dress”.

Public scrutiny also “made me quite obsessed with clothes that won’t let you down. It was awful when I’d leave the house feeling like I looked fine, and get back at the end of the day and look in the mirror and I was a crumpled mess. So I care a lot about things that travel well, and details like poppers to keep your bra strap in place, and stitching down the buttons of a shirt dress and putting a zip in the side so that nothing gapes.” One high-profile customer “works in television and likes to run into work, and she runs with a Cefinn dress rolled into her rucksack and then she can put it on and be on television and it doesn’t need ironing.”

The shock collapse of the online retailer Matches, an important shop window for many small-scale upmarket British fashion brands, is one of several factors helping to drive a return to bricks-and-mortar retailing. The high percentage of returns, which are costly for businesses and have a large environmental impact due to transport emissions of multiple journeys and unwanted clothes languishing in depots, is also a factor. The London-based brand Rixo has successfully converted its young, digitally native audience to physical shopping, opening several stores in the capital.

Cefinn sells to an affluent customer – the average shopping basket checks out at £360, although the tendency to buy multiple sizes with a view to return inflates this figure among online retail – but Cameron is at pains to downplay its poshness, describing the store location close to the ritzy real estate of Sloane Square and Knightsbridge as “convenient for both our north London and south London customers”.

Demure dresses and a range of extravagant hats in a collaboration with the milliner Jess Collett, including a version of the headpiece Cameron wore to King Charles’s coronation, speak to an audience schooled in the dress codes of the British society “season”.

“Actually, I think lots of British women dress up for events more than they did,” says Cameron. “For instance, when I got married, no one had weddings abroad, and certainly no one had hen nights or stag dos abroad – and now that has become quite normal.”

Special occasion dressing has become a bigger driver than seasonal fashion. “October is a bigger month for us than September, because it’s not the beginning of a new season that matters, it’s the moment a bit later when you start to think about what to wear for Christmas and parties – and maybe you need to buy a jumper.”

Cefinn retains strong links to the Tory party and establishment. David Brownlow, an entrepreneur who is a Tory peer and party donor, is an investor. When Cameron attended a London fashion week event for young British creatives at Downing Street in February, Rishi Sunak’s wife, Akshata Murty, who was hosting the event, wore a £180 corduroy waistcoat and matching £200 trousers, both by Cefinn, with a £120 striped shirt by another British brand, With Nothing Underneath.

Cameron has said she was unable to find “high quality” factories in Britain. “We produce in the region where the fabric comes from, for sustainability reasons.” Tailoring is made in Portugal, silk pieces in China, and cotton in India. “We work with a small number of factories that we know. And to me what matters most is that the clothes are beautifully made and finished and will be worn for ages. We’re not making throwaway things.”