Nearly two thirds of the public would feel less safe if the Government continues to cut police budgets, a survey commissioned by the Police Federation has revealed.
As the Federation's annual conference enters its second day, an Ipsos MORI poll of 1,828 people showed 63% of the public would feel less safe if the Government continues to cut the funding it gives police forces.
More than nine out of 10 - or 93% - of those surveyed said the number of police officers was important in affecting how good a job the police service can do.
And 55% said their feelings of safety were influenced by the number of officers available to their local force, with 19% unsure.
The Federation, which represents tens of thousands of rank-and-file officers, is experiencing one of the most turbulent periods in its history, facing accusations of adopting a politicised approach and claims of extravagant spending during a time of austerity.
In addition, the behaviour of some Federation representatives in the wake of the so-called Plebgate row involving former Tory chief whip Andrew Mitchell further damaged its reputation.
Mr Williams and Home Secretary Theresa May will address the conference in Bournemouth tomorrow.
Mr Williams said: "This survey surely dispels any lingering doubt that the public would be alarmed about the effect that falling numbers of police officers will have on their personal safety.
"If British policing is to be able to operate to its capacity and bring justice to the millions of victims of crime, then it is vital that we protect and increase officer numbers. Without sufficient numbers of officers, it will be ever more difficult to perform our vital role.
"The public is clearly - and rightly - concerned that without sufficient numbers of police officers, the ability of forces to protect and serve the public will be severely hampered.
"British police officers are the finest in the world. It is vital that we protect and nurture those who keep the country safe."
Total Government funding settlement for the 43 forces in England and Wales in 2014/15 has been announced at £8.5 billion, compared with £8.7 billion in 2013/14 and £9.7 billion in 2010/11.
Total central funding is projected to fall by around 20% in real terms between 2010/11 and 2014/15, as originally planned in the 2010 spending review. Officer numbers have fallen by 16,000 since 2010, the Federation said.
A total of 71% of respondents said they were confident or very confident that their local police would keep them safe, while 66% said they trusted the police to tell the truth.
The survey, carried out online between May 9 and May 12, found that 90% of the public felt safe in their local area with more than half - or 56% - saying keeping people safe was the police's responsibility.
Exactly half of respondents said their local police were doing an excellent or good job, with 34% describing their performance as fair.