Retired police officers and volunteers could be drafted in by Britain’s biggest force if Covid-19 causes staff shortages.
Metropolitan Police Commissioner Cressida Dick said she had not “ruled out any option” to boost numbers and protect essential services.
National plans have been drawn up if a fifth of officers are put out of action due to the outbreak, including moving staff from neighbourhood teams and cold case squads to frontline duties.
One option under consideration, nationally as well as by the Met, is bringing in volunteers and retired officers to help plug the gaps.
Dame Cressida said: “We need to be flexible, we are a people organisation and of course it’s likely as other people are coming into contact with the virus some of my people will as well.
“We have had plans in place for a long time to be able to move people around, to change people from one role to another, to make sure we protect the really mission-critical services.
“We have not ruled out any option in terms of boosting our numbers. We have lots of people who volunteer with the Met, we can bring them in more, and indeed there may be some areas where it would make sense to bring in some retired officers to help us out.”
Cancelling large events had already freed officers up to be deployed elsewhere, she said.
“Many events organisers are already cancelling their events including some very large events.
“It is the case that if some large events are not going ahead that gives us some people back to be able to deploy in other ways.”
The National Police Chiefs’ Council said in the worst-case scenario – where 20% of officers are unable to work – forces would prioritise emergency calls and it may take longer to get through to 101.
In the case of severe staffing shortages, forces would initially ask neighbouring areas for assistance before any national mutual aid systems were used.
A spokesman said: “When policing is under severe strain, from either demand or capacity issues, some services will have to be reduced – that could mean historic investigations that have a low risk attached to them.
“We will always focus on core policing and serious crime and the public should expect continuity of these services.”
Forces in England and Wales are working to make sure officers have access to masks and other protective equipment if needed.
Some are drawing up lists of officers with health issues that make them more vulnerable to the virus.