Councils will still have powers to impose local Covid restrictions until the autumn, despite Boris Johnson confirming that all national lockdown measures will be swept away as part of step four of the roadmap out of restrictions.

On Tuesday, Sajid Javid, the Health Secretary, confirmed that even if the final unlocking takes place on July 19 as expected, local authorities will continue to hold emergency powers to manage local outbreaks.

Mr Javid added that while it was right to be pushing ahead with "freedom day", the risk of potentially vaccine-resistant Covid variants meant ministers had to "of course remain vigilant".

"As I said… there are some powers that we are retaining, particularly for local authorities to manage any future outbreak, but the one thing no-one can say for certain anywhere in the world is the future progression of the virus itself," he told BBC Radio 4’s Today programme.

It means that while national restrictions such as mask-wearing and social distancing will switch to guidance, councils will continue to have certain powers – such as being able to shut down businesses in the case of a local outbreak – in reserve. 

They are known as "section three measures" and were first introduced last summer to give local authorities the ability to respond to imminent threats to public health from surging Covid rates. They will remain in force until September, at which point ministers will decide whether to scrap or renew them. 

On Tuesday night, a government source said: "The extension of powers for local authorities is about allowing them to close businesses if there is a threat to public health. It’s about making sure they still have that power."

The insider insisted a council would need "a very strong case for doing so", but the continuation of the powers is likely to anger some lockdown-sceptic Tory MPs, who believe all restrictions should be converted to guidance. 

Asked whether they extended to giving local authorities the power to impose local lockdowns in future, Mr Johnson’s spokesman told reporters: "This is to enable a director of public health at the local level to, if there is a significant outbreak, take the requisite public health steps to act quickly.

"I think that’s what the public wants us to be able to do. This is about sort of closing down premises and things like that, or other public health measures, it’s not meant to mimic the sort of restraints restrictions we’ve had previously." 

Asked whether the powers would be extended beyond September, he added: "We keep that under review. By September we will look at the latest evidence and data and make a decision."