Two of Britain's leading police officers have said enforcing the Government's restrictions on movement will be "a real challenge" and even impossible with the number of officers available.
Prime Minister Boris Johnson told Brits on Monday evening that they have to stay at home, apart from for medical reasons, critical work, shopping and exercise once a week.
Any gatherings of more than two people will be broken up by police, Mr Johnson said.
But Ken Marsh, chairman of the Metropolitan Police Federation, told Sky News: "It’s going to be very difficult what is put in front of us.
“I don’t doubt for one minute that my colleagues will rise to the challenge, because that’s what we always do and it’s what the public expect us to do."
Mr Marsh added that the Government hadn't told the police the details of what their new powers will be.
And he said that the police would not be able to carry out their new duties without support from the public.
"It will be very, very challenging and very difficult for us with what’s put in front of us," he said.
“But we don’t actually know what is being put in front of us yet other than we’re going to be asked to disperse crowds, it’s going to be a real, real challenge.”
He added: “One thing I would say straight off the bat to the public is please, please, you’ve got to come with us on this one, you’ve got to help with this, otherwise it’s going to get really, really impossible.”
“We will be dealing with it, but I’m not sure we will have the resources to be able to see it through."
John Apter, national chairman of the Police Federation of England and Wales, echoed Mr Marsh's plea for public support.
“Saving lives and protecting the public is the number one priority for us all and at this time of national crisis it is essential that we all come together and play our part in doing so.
“The practicalities of policing this lockdown will be challenging, but policing will do all it can to keep the public safe, but we need the public to support us... and stay at home unless absolutely necessary."
Mr Apter said this would enable police to concentrate on keeping the streets safe.
He added: “This is about saving lives and supporting our NHS, I ask that the public gives us their support in this time of crisis."
