The Online Safety Bill is intended to make tech firms accountable for harmful third-party content hosted on their platforms, ranging from illegal content such as terrorist propaganda to abusive content that falls below the threshold of criminality, such as bullying of minors.

It will be enforced by the communications regulator, Ofcom, which could block access to their sites, fine them either up to 10 per cent of annual turnover or £18m (whichever is higher), and hold senior managers criminally liable for failures of duty of care.

The regulator said it has made a good start in its preparations for implementing the new regime. But according to a report by the National Audit Office (NAO) it must now “manage risks” around monitoring, scope and financing.

The report looked at whether the preparations already undertaken are sufficiently advanced to ensure that the bill can be implemented properly. It is expected to receive Royal Assent in October and the full...