Police have been given the power to arrest people or fine them up to £960 for breaking coronavirus lockdown rules in England.
The government said the unprecedented measures were needed to “reduce the spread of coronavirus, protect the NHS and save lives”.
New public health regulations – which will expire in six months – allow police to instruct people violating the guidelines to go home, leave an area or disperse, and to ensure parents stop their children from breaking the rules.
Any adults who commit an offence under the new regulations will be handed £60 fines, reduced to £30 if payment is made within two weeks.
But if anyone has been fined for breaking the coronavirus lockdown before, the fine will be doubled to a maximum of £960.
People will not be convicted of an offence if they pay the money within 28 days, after which enforcement action will start.
“Individuals who do not pay a fixed penalty notice under the Regulations could be taken to court, with magistrates able to impose unlimited fines,” a Home Office spokesperson said.
“If an individual continues to refuse to comply, they will be acting unlawfully, and the police may arrest them where deemed proportionate and necessary.
“However, in the first instance the police will always apply their common sense and discretion.”
Under the rules, people can only leave their homes for infrequent shopping for basic necessities, one form of exercise a day, medical needs, caring for a vulnerable person or going to work if necessary.
Gatherings of more than two people in public spaces are banned, unless they are members of the same household or carrying out permitted work.
The full regulations also enforce the closure of non-essential shops and services.
Following the prime minister’s lockdown announcement on Monday, British Transport Police announced the deployment of 500 officers at railway stations to ensure “only those making essential journeys” were catching trains.
The head of the Police Federation, which represents rank-and-file officers, previously said it was “not realistic” for stretched officers to check how many times people had exercised in a day or what they were shopping for.
“Certainly the police will get involved with more than two people gathering in the same place, but as far as policing the bread aisles in the supermarkets, or checking how many times people are going to the shops, that’s simply impractical,” John Apter told BBC News.
Forces across England and Wales have already drawn up contingency plans for losing significant numbers of staff in the outbreak, which will see them prioritise emergency response, serious crimes and threat to life.
Last week, senior officers told the Home Affairs Committee they will enact a “graduated withdrawal of service” if the situation worsens, in order to maintain basic functions and support the NHS.
Police recruitment centres have closed because of coronavirus, and leaders are appealing for voluntary special constables to leave their normal jobs and for retired officers to return.
The Home Office said 1,500 additional police officers had joined forces across England and Wales since September as a result of Boris Johnson’s 20,000 pledge.
The government is allowing civil servants who are special constables to “assist in the national effort to the greatest extent possible” and will relax tax and pensions rules that deter retired officers from returning to the frontline.
Officials are speaking to the Security Industry Authority, which licences private security workers, about helping the national response to coronavirus.
Priti Patel, the home secretary, said: “All our frontline services really are the best of us and are doing an incredible job to stop this terrible virus from spreading.
“That’s why I’m giving the police these new enforcement powers, to protect the public and keep people safe.”
The announcement came hours after the Crown Prosecution Service (CPS) said people who deliberately cough on emergency workers during the coronavirus outbreak will be jailed for up to two years.
Coughing will be charged as an assault on an emergency worker, or common assault if used against other key workers or members of the public.
The intervention came amid numerous reports of police and shop workers being deliberately coughed at by people claiming to have coronavirus.