Meanwhile, research by financial service provider Nutmeg, says that just one in five women are the main breadwinner in their relationship. While couples in their twenties are most likely to feel that this salary gap causes tension. So what do the politics of the salary gap look like in practice? And where does that leave those of us who strive for an equal relationship but can’t rival our partners’ pay packet?
For the first four years of our relationship, as students, my partner and I operated on a totally level financial playing field. We paid 50:50 for everything, from rent and bills to nights out. But from the moment I followed my dream into journalism – and he followed his into the far more lucrative world of software developing – there’s inevitably been a gap between our salaries. And, unless either of us opts for a drastic career change, that’s not likely to reverse any time soon.
Leah, 23, an events coordinator, tells me her fiancé earns almost double her salary working as an engineer. “We split the rent and bills 60:40, which goes out of a joint account, but we keep our separate accounts too for disposable income,” she explains. “This means I have a little more to spend on doing fun things together than I would have if we split down the middle.”
When it comes to holidays and going out, Leah says, “we tend to split 50:50”. And living with a fellow “clean freak” has proved an effective way of ensuring that household duties are also shared out evenly. “I do cook every night and try to do a bit extra to make up for my shortfall, but I think this is predominantly subconscious,” she admits.
Entrepreneur Rachel, 32, tells me she and husband Simon, a campaigner, are “common potters who treat both of our incomes as shared” and “split daily [household] tasks fairly evenly”. Any tension about the difference in their incomes, she says, “is entirely on my side. He is happy to financially support me – partly, because he thinks my work is important, and partly because he sees this as a temporary thing. Either the work I am doing now pays off and our income gap shrinks, or it doesn’t and I go back to a salaried job.”
Yet guilt is a common theme for both women.
“At the start, I worried that I wasn’t paying my way – especially after a girl he works with joked that there should be 10 per cent of the flat that I don’t have access to,” Leah says.
Rachel is concerned about an impact on the equality of their relationship. “Being dependent on my husband makes me feel like a leech. I think the knowledge that I’m dependent creates a lot of guilt, and a little bit of resentment, on my end,” she says.
I’m struck that both women describe their guilt as self-inflicted. Indeed, what struck me while writing this piece was that of all the women I spoke to, those who felt the least guilt about their situation were those whose salary gap exists in part because of their decision to alter their work situations to raise children.
Kate, 40, says: “if I had continued to see my career as important – as I thought I would – I would have gone back to work. But the moment I had my son my work seemed so pointless. My time with our children is far more valuable than his time at work.”
Kelly, 34, meanwhile, has been on both sides of the salary gap. She previously worked as Head of European Communications for a high street retailer. “When I first met Steve I earned almost double his salary,” she explains. “When I was the bigger earner I was very independent. I owned my own house and car outright, and always paid at least 50 per cent of our dates.”
After having her daughter in 2012, Kelly began working freelance and part time, while Steve, 37, retrained in accountancy and is now the main breadwinner. “I can certainly say it does change things,” Kelly says. “At first it was a little difficult to adapt and I over compensated for my salary by other means. I naturally wanted to feel equal and – even though raising our daughter was and is a full time job in itself – I wanted to provide more by making lunches, preparing dinner and doing housework.”
Of course, with the gender pay gap hovering around 16 per cent(and women essentially earning 80p for every pound a man makes), we’re already on the back foot. Even in female-dominated industrieswe’re paid less than men.
As Rachel says: “I imagine most readers wouldn’t be sympathetic to my situation. But my partner and I both believe that I am contributing more to society in the work I am doing currently than I have in previous roles, even if that work is not compensated economically.”
Indeed, much of our discomfort around the salary gap – both at home and in the wider world – seems to come from a sense that we’re letting ourselves, our partners, and maybe even the whole of the women’s liberation movement, down by working in roles that we love – those jobs that we feel have most social importance – rather than bringing home the bacon, now that we feasibly can.
“On reflection,” Rachel adds, “it isn’t the fact that there is a salary gap that bothers me, so much as the feeling that I’m an ostensibly professionally ‘successful’ adult who doesn’t earn enough money to support herself. It’s an embarrassing thing to admit, even under my first name only.”
Do you think a salary gap can work in a relationship? Join the conversation with Telegraph Wonder Women and Sarah Graham on Twitter.