After government scientists cautioned that deaths may soar without urgent action, Johnson stopped short of another full lockdown as he did in March but said further action could be taken if the disease was not suppressed.
"We reserve the right to deploy greater firepower, with significantly greater restrictions," Johnson told parliament following emergency meetings with ministers and leaders of the United Kingdom's devolved governments.
Just weeks after urging people to start returning to workplaces, Johnson advised office workers to stay at home if they could. He ordered all pubs, bars, restaurants and other hospitality sites to close at 10 p.m. from Thursday with only table service allowed.
It was unclear if the measures would be enough to tackle Britain's second wave, which government scientists warned could reach 50,000 new cases per day by mid-October, or what the cost would be for the world's fifth largest economy.