More needs to be done to ensure London's emergency services can cope with hosting the 2012 Olympics, a London Assembly report has said.
Uncertainty about funding ahead of the government's spending review has hindered emergency planning, according to the Business as usual? report.
The Metropolitan Police (Met) told the assembly it would be "very, very stretched" during the Games.
Meanwhile, London Ambulance Service said it would need 300 extra staff.
London Fire Brigade said it feared a £900,000 shortfall for its cover during the Games.
The Met told the assembly the Olympics would be the biggest peacetime operation they had undertaken.
"All emergency and health services are facing a core funding squeeze in the current financial environment," the report said.
"Funding for all of London's emergency and health services is one key unknown variable which may have an impact on their preparedness for the Games and ability to provide business as usual services."
James Cleverly AM, chairman of the London Assembly health and public services committee, said: "2012 will be an unusual year and London's health and emergency services will be under extraordinary pressure."
As well as the Games, emergency services will also have to handle celebrations for the Queen's Diamond Jubilee, a WorldPride gay parade and the Notting Hill Carnival.