A grim-faced Prime Minister walks to a podium and delivers a sombre message to the British public that their lives are about to be disrupted in the most dramatic and fundamental way. This may sound like one of Boris Johnson’s televised addresses during the Covid pandemic, but it is in fact a scene from a new Channel 4 drama, The Undeclared War, about another potentially devastating threat from an unseen force: a major cyber attack that could bring the nation to a standstill.

The six-part series, directed by Peter Kosminsky and starring Adrian Lester as the Prime Minister, Simon Pegg as head of GCHQ and Hannah Khalique-Brown as an intelligence officer, is the result of five years of extensive research about what could happen in the event of a widespread hack on computer networks affecting government, the NHS, national infrastructure and banks. In fact, there are many comparisons with the Covid pandemic, and not only due to the viral nature of malware.

While the impact of a major cyber attack may stretch out for more than two years or more, as it did with Covid, experts warn there are gaps in the emergency planning by world governments to deal with such a crisis, just as they were underprepared for the pandemic. Planning for a viral pandemic was always about a worst case scenario that ministers, public health officials and scientists hoped would never happen – and so it is with a cyber attack.

But experts believe governments, businesses and the public need to take the threat, which may seem abstract, more seriously. They hope The Undeclared War, set in the very near future, will bring it to life. The ongoing reality of war in Ukraine, which has fuelled high inflation and food and energy insecurity, brings an added dimension to fears of a major cyber attack.

The worst case scenario is so much more than a website going offline for a few hours, but critical national infrastructure (CNI) such as water reservoirs, gas and oil pipelines and refineries, the NHS, supermarkets and transport networks being disrupted, with the aftermath lasting several days as the public panics to stock up on dwindling supplies and hospitals cannot operate on patients or conduct MRI scans.