London's robotaxi rollout is running behind the ambitious schedule set out by the UK government, with the three main operators now unlikely to launch a fully driverless commercial service this year. Alphabet's Waymo, Uber-backed Wayve and China's Baidu still face regulatory or technical barriers before they can take paid passengers without a "safety driver" behind the wheel.

Any delay will come as a relief to cab drivers worried about job losses, but could dismay the 100,000 people who have signed up to try Uber and Wayve's service. Ministers, investors and tech executives had hoped the launch would help position the UK as an innovation hub. Vehicles are now available in more than 20 cities across the US, China and the Middle East, with Zagreb becoming the first European city to offer autonomous rides this month.

Progress has slowed as the new Prime Minister Andy Burnham has hinted at a less enthusiastic stance towards technology companies. Transport for London has yet to publish the guidance companies must follow to win approval. Jack Stilgoe, tech professor at University College London, said: "It's not clear whether Andy Burnham shares that enthusiasm. TfL are still asking what problems this would actually solve."

Many in the industry expect Waymo to take an early lead in London. The company, which raised $16bn in February and operates in 11 US cities, is testing about 100 vehicles in the city.