Barking and Dagenham Council leader Darren Rodwell has criticised the government's lifting of Plan B Covid measures, branding the move "counterproductive".
The Labour politician has written to health secretary Sajid Javid with his concerns about the decision.
Advice on working from home has been scrapped, while mandatory rules on wearing face masks are also to end.
But London mayor Sadiq Khan announced face coverings would still be required to travel on public transport in the capital.
Cllr Rodwell said: “While I respect the government’s decision, I have to put on record my objections to the sudden change in everything we have told people to do over the past 20 or so months and throughout the pandemic.
“We have consistently told people to wear face masks on public transport and other enclosed places as it helps to prevent the spread of a virus, which unfortunately is still with us and is ravaging communities."
In the council's Covid update on January 20, Cllr Rodwell confirmed there were 1,880 new cases of the virus in the borough during the previous week.
Government data as of January 18 showed only 57.6 per cent of the borough's residents have had two Covid jabs, falling to 34.5pc for three jabs.
These are among the lowest rates across the country.
Cllr Rodwell thinks the loosening of Covid restrictions "will do more harm than good".
“I am going on the record to say that this announcement is counterproductive and will make an already difficult job of getting people to keep themselves and their loved ones safe, take the vaccine and the booster a lot more difficult.
"As a borough we will continue to follow the scientific evidence to do the best by and for our communities."
During a press conference on Wednesday (January 19), Mr Javid said data supported opening the country up again.
The minister said the government is still suggesting face masks are worn in enclosed and crowded spaces, especially with people who are not regular contacts.
He added: "The steps that we’ve announced represent a major milestone. But it’s not the end of the road and we shouldn’t see this as the finish line.
"Instead, we must learn to live with Covid, in the same way that we’ve learned to live with flu.
"The best step that we can all take is to get vaccinated."
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