The UK’s cybersecurity chief warned that Britain faces what could prove to be an unprecedented increase cyberattacks in the coming months and urged “willfully blind” businesses to come to terms with the risk.

Richard Horne, head of the National Cyber Security Center, delivered the stark message to firms in a speech on Tuesday in which he said the country was at a “sliding doors” moment as threats from Russia, Iran and China rise.

“In the coming months, we face a real prospect of an unprecedented rise in the number of cyberincidents,” he said. “Far too many of our organizations and supply chains rest on weak technology and operational foundations.”“When food isn’t on the shelves, when lights aren’t on, businesses have gone under, we may have to explain that we saw the warning signs, understood the risks and still didn’t make the right choices. Why we remained willfully blind,” he said.

The warning comes amid a raft of high-profile cyberattacks and growing concerns that artificial intelligence tools are accelerating the cat-and-mouse game between hackers and their targets. Supermarkets across Europe were hit by suspected cyberattacks that resulted in sudden changes in the temperatures of their fridges and freezers on Monday, with a small number of British firms affected, according to Horne, following a similar issue last month in France.

In his speech, Horne accused Russia of working “every day” to attempt to penetrate Britain’s military networks, and said Iran was carrying out “malicious cyber operations globally including against the UK.”The British chief chief said that China posed the most serious challenge to Britain, assessing that Beijing “highly likely has the intent and is best positioned to use AI for operations against our critical national infrastructure and other strategic targets.”China represented “the most sophisticated and sustained cyber challenge the UK faces,” he said.