Samantha Cameron: I can't afford designer clothes - I have kids and a mortgage

As the wife of a former Prime Minister and with a successful career of her own, Samantha Cameron might appear to have few money worries.

But Mrs Cameron has claimed that mortgage and childcare payments put such a squeeze on the family finances that she cannot afford designer clothes.

That was the motivation, she said, for starting her own fashion company. The womenswear brand, Cefinn, is more expensive than the High Street but cheaper than designer labels, with the average price for a dress around £260.

She launched Cefinn in July last year, the same month that David Cameron left Downing Street - and weeks after the couple reportedly took out a £3.5 million mortgage on a new home.

The label “came out of a very personal need”, she told an audience at the FoundHER Festival for women entrepreneurs.

“I had been working in the luxury/fashion business [as creative director, and later consultant, for Smythson] for a long time and didn’t have disposable income, with childcare and mortgage etc, to buy designer clothes.

“But obviously, working in the fashion industry, I wanted to find workwear and daywear that had a bit of a fashion edge, that felt a bit cleaner, younger, more modern than what was available. So it was a feeling that there was a gap in the market.”

Mrs Cameron said she had endured sleepless nights and “answering emails at 4 o’clock in the morning” as she launched the label, with the website going live in February.

“It’s been incredibly hard work, and frightening… in the beginning it’s tough, you’re doing it on your own and it’s kind of lonely,” she said. “I feel like I’ve come out the other side, but that initial starting point was really hard.”

Mrs Cameron has previously disclosed that she buys most of her husband’s clothes from Marks & Spencer. However, the idea that an ex-Prime Minister’s wife lacks disposable income comes as something of a surprise.

His historic tax return published in April last year showed that he had no fewer than six sources of taxable income, including his £140,000 salary as Prime Minister, rental income from his £2 million home in Notting Hill, interest on savings and dividends from shares.

Three months after leaving Downing Street, he reportedly picked up more than £120,000 for an hour-long speech to Wall Street financiers in New York.

Mrs Cameron, 46, the daughter of a baronet, worked for Smythson for 20 years and said her management style has improved in that time.

“In my 20s, I managed my staff a bit differently than I do now. It was a bit, ‘If you can’t keep up…’ Whereas I now try to be as grateful as possible, and just remember that my team are putting in the hours. I hope I’ve got better at that. Remember that the people around you are working hard and have issues and you need to support them.”

Mrs Cameron hails from a comfortable background.

She is the elder daughter of Sir Reginald Sheffield, 8th Baronet and a direct descendant of Charles II, and grew up at Normanby Hall, a 300-acre estate in Lincolnshire.

When neighbours complained about the presence of 400ft wind turbines on the estate in 2011, Sir Reginald protested that they only generated a "modest income" of "less than one-tenth of £3.5 million".

Her mother, Annabel, later re-married, to William Astor, and is now Viscountess Astor, who founded the Oka furniture chain. It is from her that Mrs Cameron inherited her entrepreneurial spirit.

In 2006 she was said to have received £300,000 from the sale of Smythson, and a further £50,000 when it was sold on three years later.

The couple's financial affairs were in the spotlight last year when Mr Cameron admitted he and his wife owned shares in an offshore fund set up by his late father, Ian.

Details of the fund were contained in the leaked Panama Papers. Mr Cameron said he and Mrs Cameron sold the shares for £30,000 in 2010 and had paid all UK taxes due on the profits.