27/01/2016 12:44 GMT | Updated 27/01/2017 05:12 GMT

Until the Mayor Takes Action on Rents, Young Londoners Will Keep Their Lives on Hold

For Londoners in their late 20s and early 30s it's a familiar tale. You leave education just as the economy hits the buffers. The lack of jobs in the provinces propels you to the capital as the only way to make use of that expensive degree. The demand for somewhere to lay your head means tolerating cramped accommodation with annoying flatmates, and hoping that swift career progression will buy you some breathing space.

In time you might have met the love of your life and are finally at a point where both your pay packets can stretch to a one-bed flat in Zone 3. As your carefree early 20s recede into a distant memory, you start thinking about babies.

It's perfectly natural. Your parents had probably reached the same conclusion by this point. But if you thought starting a career was difficult, the odds are really stacked against starting a family. We already know how hard it is to buy a home in the capital, but new analysis by Generation Rent suggests that having a kid - that basic building block of society - is increasingly unviable.

The cost of rent on the median two-bed flat - one bedroom for you, the other for Junior - costs 52% of the median London salary. For housing to be considered truly affordable, it should cost no more than 30% of your income. There is not a single London borough where this is the case - not even in the wilds of Havering, where the typical single-earner household would spend 35% of their income on rent.

Obviously if you're earning more or have managed to find a bargain, it's easier to make it work, but the numbers indicate that around half the population will be unable to have that ultimate rite of passage. This is reflected in recent polling from London First that found 46 percent of twentysomething women were less likely to raise a family in London due to housing costs.

That leaves broody couples with a conundrum: do they pay for childcare so the stay-at-home parent can go back to work after statutory parental leave ends? If they're on a typical salary, the £22,000 a year for pre-school care is unlikely to be worth it.

Why not move out of the city? Rent in Hastings is £565 a month compared with £1450 in London as a whole. But commuting will set you back another £439 a month, and you'll spend about 3 and a half hours every day on a train instead of watching that person you created grow up.

The only real options are either to leave London entirely, or give up on having a family. If the next Mayor doesn't take drastic action on the cost of housing, they will drive away workers and their children, leaving a hamstrung economy and eroding communities. London is a world city and an engine of the UK economy but it will only remain so if everyone is able to make a decent living.

The first thing the new Mayor can do is start building genuinely affordable homes. Currently, anything that costs 80% of market rent is treated as "affordable" under the Mayor's quotas, but that is still not affordable for a typical family on a single income. Generation Rent is calling on the Mayoral candidates to commit to defining affordable as costing no more than 30% of the poorest quarter of the population's income.

As polling day approaches, Generation Rent is keeping track of the candidates' policies on its new website, We and our supporters will be putting pressure on all the candidates to offer voters a plan to fix the housing crisis, by building enough homes, improving protections for renters and most importantly reducing the cost of rent. Until then, too many renters have put their lives on hold.