The Government will launch a new drive to alert the public to the threat of cyber attack, amid warnings that Britain's critical national infrastructure could be a target.
Cabinet Office Minister Francis Maude is publishing an update of the Government's cyber security strategy, including fresh measures to improve the UK's ability to detect and defeat "high-end threats".
Officials acknowledged that "hostile foreign states and others" had targeted the systems controlling the UK's critical national infrastructure such as power and water supplies.
They would not be drawn on the countries involved although it has been reported that both Russia and China have carried out the reconnaissance necessary to mount a cyber attack on the US's national infrastructure.
"There is still a concern about a determined attack against the critical national infrastructure," said one UK official.
Officials say they now spend "an awful lot of time" advising Britain's infrastructure companies to guard against such online onslaughts.
Speaking before publication, Mr Maude said the entire country needed to become more "cyber savvy".
He said: "The internet transforms the risk we face. It is why we have rated attacks from cyberspace one of the top four threats to our national security.
"We are in a race to build sufficient cyber defences to match the growing volume and dependence of our online economic, security and social interests.
"It's a race we can only win by working together: Government, industry, academia and the public. This is as much a shared responsibility as a shared effort."