Electric motor racing series Formula E burned up a net loss of £29.8m last year as start-up costs accelerated.

The series, which began in 2014, is the first all-electric single-seater racing championship. Its cars are powered by a 200kW motor giving them a top speed of 150mph which is around 30pc slower than their bigger brothers in Formula 1.

Manufacturers such as Audi, BMW and Renault use the series to show off their green credentials and it has signed up a string of city centre tracks as the cars produce no emissions and little noise.

Its Hammersmith-based holding company, Formula E Operations, made a net loss of £49.4m in its first season and although this narrowed by 46pc in the year to 31 July 2016, accounts say this was driven by taking on broadcasting and sponsorhip agreements that were previously held by another company in the group.

Costs rose by 9.6pc to £76.3m and outstripped its £47.8m of revenue. The company covered the deficit with £38.5m of loans from its Hong Kong-based parent Formula E Holdings (FRH) and its net liabilities accelerated in line with this to £90.5m.

The biggest shareholder in Formula E is held by Liberty Global, the owner of television network Virgin Media and a shareholder in ITV.