Despite stating that Tech City is the biggest revolution in human history, David Cameron's ambassador to the project believes that high rent in London is driving start-ups abroad.

Ben Hammersley is also editor-at-large for Wired magazine UK and spoke at Queen Mary, University of London about Tech City, saying that high rent prices in the country's capital is a huge problem.

"The biggest threat to London as a start-up community is rent," Hammersley said, before adding that start-ups and software engineers are finding other tech-driven cities like Berlin and Amsterdam to be much more affordable.

Earlier in the talk on 23 April, Hammersley praised Tech City for being at the forefront of the biggest revolution in human history; he spoke of 'smart cities' where everything from weather conditions to traffic and congestion would be monitored by sensors and connected over the internet, providing real-time information.

The Wired editor-at-large suggested that curbing the problem of high rent in and around Tech City would be a "40-year project" and claimed that he had spoken to "many people at Facebook and Google and so on who have seen their engineers living eight to a house because it's not financially viable [to live in separate houses.]"

Hammersley added: "A lot of early stage start-ups who are geographically independent are upping sticks and moving to Berlin...not because Berlin is nicer - in fact it's freezing in winter - but because if you've only got so much money left to invest, you can burn it four times faster here [London] than over there."

The point of Tech City, Hammersley explained, is, in his view, not to make application developers into billionaires, but to enrich and build on the local community of Shoreditch and east London as a whole.

As such, Hammersley is concerned not just about the living standards of the capital's software engineers, but of everyone in the local area.

"I've heard people say that maybe we can make the Olympic village into cheap housing for software engineers, but more than software engineers need to come and live here; primary school teachers and ambulance drivers and firemen and so on, and that's a huge social problem as well - the fact that public service workers don't live in a place that they work. "

Summing up, the PM's ambassador to Tech City said: "So rent is a big thing, it's the one thing that would make me leave this city and I know a lot of people who are free to live anywhere, but who are thinking that very thing.

"And the fact that it hailed yesterday is ridiculous."