“It’s quite unusual for a government to publish a plan with things in it we hope we won’t have to do,” Health Secretary Matt Hancock told the BBC. Johnson’s government has been accused of being slow to respond to the illness, which was first identified late last year in China. So far, Britain has fewer cases of the disease than some other European countries such as Italy and France, with only 40 confirmed infections. But officials say a much wider spread of the disease is likely.

“It may be that widespread exposure in the U.K, is inevitable, but slowing it down would still nonetheless be beneficial,” the government document says. Scientists are still racing to learn about the new virus, and Britain says it is prepared for a range of severities — from the equivalent of a mild winter flu outbreak causing a few hundred deaths, to something like the 1918-1919 influenza pandemic that killed an estimated 200,000 people in Britain and tens of millions worldwide.

British experts have previously said a worst-case scenario could see 80% of the U.K’s 66 million people become infected, with 500,000 deaths, though they stress they do not think that is the most likely outcome.

For now, experts say they best thing people can do to stop the disease spreading is the simplest: wash hands frequently with warm, soapy water. U.K. authorities say they may have to close schools, cancel mass-attendance events and tell large numbers of people to work from home as part of “social distancing strategies” designed to delay the spread of the disease until summer, when flu season is over and pressure on the health service lessens.

Retired doctors and nurses could be put back to work to ease medical staff shortages, and school class sizes could be increased if teachers fall ill. The U.K. government says more drastic measures if it spreads widely could include rationing of medicines and a stripping back by emergency services to their “critical functions.”

“For example, with a significant loss of officers and staff, the police would concentrate on responding to serious crimes and maintaining public order,” the document says. The government says its strategy aims to protect those most vulnerable to the disease: the elderly and those with underlying health conditions.

It also raises the prospect of many extra deaths, and says the government “will provide advice to local authorities on dealing with this challenge.” The action plan notes that in the event of a widespread outbreak, “pressures on services and wider society may start to become significant and clearly noticeable.” It says actions will only be taken on the advice of the government’s medical experts.

The government also plans new legislation to ensure it has “all the necessary powers” to respond to the outbreak. It has not revealed details. British media report that the legislation is likely to give border officials the power to deny entry to anyone suspected of carrying the virus, while the government may also get the power to close schools and prevent mass public gatherings.