LONDON — British Prime Minister Boris Johnson has warned that authorities will have to impose tougher measures to combat the spread of COVID-19 and “protect’’ the Christmas holidays.

Johnson’s comments come amid reports that the government is set to impose a 10 p.m. curfew on pubs and restaurants in northern England in response to a recent jump in infections.

Writing in the Sun newspaper on Thursday, Johnson says the only way to be certain the country can enjoy Christmas “is to be tough now.’’

He says that he wants to “stop the surge, arrest the spike, stop the second hump of the dromedary, flatten the second hump.”

Over the past two days, opposition lawmakers criticized Johnson’s handling of the COVID-19 crisis, accusing the government of lacking a cohesive plan to tackle the second wave of the pandemic.

Figures released late Wednesday showed 3,991 new confirmed U.K. infections during the previous 24 hours, up from 3,105 a day earlier.