Skyscrapers in the City of London could soon be built by robots rather than by people, according to the boss of one of the UK’s biggest construction firms.

The result would be huge productivity gains as more work could be done by fewer people – but also mass layoffs as traditionally labour-intensive construction projects hire fewer and fewer staff.

“We’re moving into the era of the robots,” said Alison Carnwath, the chairman of Land Securities, the £8.2bn FTSE 100 construction company.

Speaking at the Institute of Directors’ annual convention, the veteran businesswoman said the pace of technological change has taken her by surprise.