Hackney’s population has rocketed by over 40,000 in the last 10 years and now tops 246,000, newly-released census figures reveal.

The massive increase led to suggestions this week that the size of the borough’s population had been underestimated in previous national censuses.

It sparked mounting concerns about the impact a rapidly growing population is having on already overstretched council and health services undergoing funding cuts.

The 2011 census showed Hackney’s population is the third fastest growing in London, up by 18.9 per cent since 2001.

Meg Hillier, MP for Hackney South and Shoreditch, said: “I’m not surprised about the increase at all. There has been a baby boom nationally and I am part of it; I have a three-year-old.

“We knew there was a projection of a need for new school places in Hackney and because Hackney is a young population we have a high birth rate.”

She said this would put pressure on school places, maternity services and doctors’ registers in particular.

“Having a young population is a positive thing. It makes us a very vibrant area but we need to make sure we plan future service provision,” she added.

Mayor of Hackney Jules Pipe said: “For years we’ve been making the case to the Office of National Statistics and the government that the population of Hackney has been significantly undercounted and that this has had an adverse impact on the funding allocated to the borough.”

Diane Abbott, MP for Hackney North and Stoke Newington, said she was surprised by the sharp population increase but added: “I suspect this reflects the fact that Hackney’s population has in fact been undercounted in the past.

“I think these new census figures more closely reflect reality.”

In 2001 over a quarter of Hackney’s population did not complete the census but in 2011 86 per cent filled it in.

The resulting 2011 census population was 14 per cent higher than mid-year estimates.

Mr Pipe added: “The council is facing significant cuts in government funding over the next four years so it’s important Westminster has an accurate idea of the borough’s population and its needs.

“It means we can fight for a fair deal for our residents over the next decade.”

Overall London’s population has increased, but not as dramatically as Hackney’s. Now 8.2million live in the capital, 900,000 more than in 2001.