Johnson says lockdown lifting will be cautious, irreversible

"We've got to be very prudent and what we want to see is progress that is cautious, but irreversible," Johnson told reporters. "If we possibly can, we'll be setting out dates."

"If because of the rate of infection, we have to push something off a little bit to the right - delay it for a little bit - we won't hesitate to do that."

Johnson, who will set out his plan to lift lockdown on Feb. 22, said the rates of infection were still very high and that too many people were still dying.