The start-ups cover a variety of sectors including e-commerce, fintech, data and analytics, edtech, hardware, IoT and healthtech. The average number of employees among the companies is 30, and 90 per cent of the start-ups were incorporated within the last six years.

Gerard Grech, CEO of Tech City UK, said: "Upscale from Tech City UK is a grassroots initiative to coach the next generation of UK-based entrepreneurs. Upscale has been built from the ground up, using direct feedback from company founders, investors and ecosystem partners. I'd like to welcome everyone aboard and thank all of our advisors and friends who helped this take off."

In order to qualify, start-ups had to be based in the UK and either funded up to Series A or with 500,000 in revenue and growing at 40 per cent month over month on a key business metric such as active users, subscriptions, or sales.

As part of the government-supported programme, the companies will get access to specialised 'scale coaches', including Skype founder Niklas Zennstromm, over a six-month period.

Tech City UK has announced the line-up of its Upscale programme , choosing 30 digital start-ups to join based on their potential for scaling and international growth.

The roster of 'scale coaches' includes Skype's Zennstrom, Techstars co-founder Brad Feld, and Unruly co-founder Sarah Wood. Silicon Valley Bank and law firm Cooley LLP will also act as programme partners and will give participating companies financial and legal advice on scaling.

"Great entrepreneurial ecosystems are all about putting people together and letting them learn from each other through multiple, intense, deep interactions," said Suranga Chandratillake, partner at Balderton Capital and an Upscale advisor. "Upscale is facilitating precisely this with some of the most interesting young companies in Britain today something that will be hugely valuable to the companies themselves, the digital ecosystem in the country, and the wider economy."

Tech City also runs the Future Fifty growth scheme for the UK's fastest growing scale-ups, with companies on the programme revealed to have raised 470 million in the first nine months of 2015 - 63 per cent more than they had received in the whole of 2014.

Sarah Wood, co-founder and co-CEO of Unruly, said: "Scaling UK start-ups further and faster is now the most pressing challenge for UK PLC. Only by working together and sharing our expertise can we ensure that as many UK companies as possible go from start-up to scale-up and contribute to the future growth of the UK's digital economy."