YOUNG families in their thousands are being priced out of London, Britain’s largest renters’ group warned yesterday.

According to the latest data from the Office for National Statistics (ONS), the number of 30-somethings with young children fleeing the capital due to high rents has jumped by a quarter since 2012.

Generation Rent told London mayoral hopefuls yesterday that failing to stop rising rents would impede London’s economy, “weakening its communities.”

The group’s director Betsy Dillner said: “After years of pressure on Londoners, the cracks are starting to show.

“London is an incredible city and the decision to move away isn’t taken lightly.

“These people are leaving friends and family in order to find a home they can afford and some are leaving their jobs.

“This should worry everyone in London — from employers facing a loss of skills to communities losing valued neighbours — and especially the next mayor, whose job will be to stop this exodus.”

In 2013-14, nearly 26,000 more young families moved out of London than moved in, a 25 per cent rise from 2011-12.

This outflux coincided with a rise of nearly a third in London’s house prices and a 6 per cent increase in rents.

The number of people under the age of 40 moving to London has also started to slip.

Labour’s City Hall housing spokesman Tom Copley told the Star that “an exodus from London is not just a personal tragedy for those forced to leave but is increasingly a problem for the capital collectively.

“We need people on low and middle incomes to be able to live here to do the jobs that keep our city going and to ensure that our city remains a vibrant diverse metropolis.

“These figures underline the importance of electing a new mayor who will get City Hall intervening directly to build the homes we need and who will push the government to devolve powers to better regulate private tenancies to create more stability and affordability for tenants.”

Mr Copley joined Green Party mayoral candidate Sian Berry and representatives from the Conservatives, Lib Dems and Ukip at a debate last night hosted by Generation Rent, Renters’ Rights London and PricedOut.