Prime Minister Boris Johnson has urged the public to behave responsibly as the lockdown is eased.
In his latest COVID briefing, Mr Johnson praised workers in pubs, hotels and the tourist industry for their efforts in keeping businesses afloat.
But he added: "We must not let them down. Lockdown only succeeded in controlling the virus because everyone worked together, and we will only succeed in reopening if everyone works together, because we are not out of the woods yet.
"The virus is still with us and the spike in Leicester has shown that.
"If it starts running out of control again, this Government will not hesitate in putting on the brakes and reimposing restrictions.
"Anyone who flouts social distancing and COVID secure rules is not only putting us all at risk but letting down these businesses and workers who have done so much to prepare for this new normal.
"So as we take this next step, our biggest step yet on the road to recovery, I urge the British people to do so safely."
The Prime Minister also said a more localised approach to dealing with outbreaks would be adopted.
He outlined a five-point strategy involving monitoring, engagement with local agencies, testing, target restrictions and - as a last resort - lockdown.
Mr Johnson also revealed that a schedule for the reopening of remaining closed businesses such as gyms and nail bars would be announced next week.