United Kingdom govt to change law to enforce Leicester lockdown
He added: 'We have been monitoring it incredibly closely, and we have put in extra testing units.
Mr Hancock said Leicester's seven-day infection rate is 135 cases per 100,000, which is three times higher than the next highest city.
Local leaders have criticised the slow response from the Government and Public Health England (PHE) in sharing case and testing data in Leicester. I understand this is disappointing news for residents, parents of schoolchildren and businesses when most of the country is opening back up but it's crucial that people follow the latest advice.
He continued: "Unfortunately, the clinical advice is that the relaxation of shielding measures due on July 6 cannot now take place in Leicester".
Leicester accounted for 10 percent of all positive cases in England in the past week, the government said.
"Instead, we need to ask real questions about the adequacy of the UK Government's response to this whole crisis and whether it has, most immediately, failed the people of Leicester".
This means the city's bars, restaurants and hairdressers will not open on 4 July, unlike the rest of England.
Suburbs of Leicester, such as Oadby, Birstall and Glenfield, will also be affected, and the health minister said details of the wards in Leicestershire covered by the new lockdown measures would be published "imminently".
"But with the interest of the people of Leicester in our hearts, I want everyone in Leicester to know that we've taken every one of these decisions to protect them from this awful virus".
However that had still not happened early on Tuesday just a few hours before the restrictions on shops were due to begin.
Mr Hancock said that "in some cases" the coronavirus lockdown will be enforced by the police, with legal changes brought in to ensure non-essential retail is no longer open.
He told the Commons: "These actions are profoundly in the national interest too because it's in everyone's interests that we control the virus as locally as possible".
"I know that this is a worrying time for people living in Leicester and I want you to know you have our full support".
"Local action like this is an important tool in our armoury to deal with outbreaks while we get the country back on its feet".
Regarding travel restrictions, the Health Secretary said "we will if we have to", but he added he hoped people in the city would "do the right thing". We know younger people have been less likely to comply with lockdown rules.
But Leicester mayor Sir Peter Soulsby said he had not had data on whether garment factories in the east of the city had seen "hotspots" for the virus.
Schools in the city, where the remains of King Richard III of England were found under a vehicle park in 2012, will close again from tomorrow, with Mr Hancock saying there had been an unusually high incidence of infections in children there.
The United Kingdom has been the European country worst-hit by the coronavirus pandemic in terms of fatalities, with the death toll from confirmed cases of Covid-19 now standing at 43,575.
The exact boundaries are expected to be set out by the government later on Tuesday.