A damaging Tech City brain-drain would follow British exit from the European Union with tens of thousands of European developers forced to apply for visas, the boss of a coding school recently established in EC1 has warned.

“Coders from Eastern Europe will simply move to France or Germany who have similar skills problems rather than bother with the hassle and expense of visa applications,” says Eric Dodds, CMO of US Iron Yard which has opened its first school outside the US in Clerkenwell.

The skills gap is one of the key issues that is holding back the growth of clusters like Shoreditch’s Tech City whose startups frequently call on the expertise of migrants from Romania, Poland and the Baltic countries, who have benefited from the focus on science and mathematics in former Soviet bloc schools and universities.

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Telecoms company O2 has predicted that the UK will have to find 750,000 workers with digital skills by 2017 in order to keep up with the pace of change. On current trends London alone will have 21,000 vacant digital positions in the next two years.

Just seven successful visa applications were made through the Government’s Exceptional Talent Visa Scheme in the last 12 months since Tech City UK was added to the Government scheme.

“The solution is to train a ‘home grown army’,” says Mr Dodds. “The UK’s skills crisis means there is a huge appetite in London for courses that can turn out experienced developers in just 12 weeks, both from an employer’s point of view as well as from employees who are in a sellers’ market especially if the Eastern Europeans move on.”

A recent Select Committee report into the digital economy, said the UK was “lagging behind” its competitors in IT training and the National Audit Office said that it would take the UK 20 years to bridge the skills gap.