Chancellor Rishi Sunak has suggested that self-isolation for those pinged by the NHS app could be altered as coronavirus cases are expected to spiral.

Acknowledging public “frustration”, he said on Thursday that Health Secretary Sajid Javid is looking at an “appropriate, balanced and proportionate” approach for the app.

Most of England’s remaining lockdown restrictions will end if the Government proceeds with Step 4 on July 19, but changes to self-isolation rules will not come in for another four weeks.

Ministers have been warned that millions of people could be “pinged” by the app or ordered to self-isolate by Test and Trace, with infections expected to hit around 100,000 cases a day in the summer.

Mr Sunak told Sky News: “I’ve spoken to the Health Secretary about this and he’s aware of the frustration that people have around this.

“I know most people’s concerns rest with how the app is working, and the Health Secretary is aware of that.

“The app counts for the majority of the people who need to isolate, I understand, on the numbers, and he’s looking at what the most appropriate, balanced and proportionate approach to isolation is in these circumstances.”

He added on BBC Breakfast that Mr Javid will be “looking at the difference between those two systems” of the app and NHS Test and Trace.

Labour leader Sir Keir Starmer warned on Wednesday that the plans to end restrictions could lead to a “summer of chaos and confusion”.

He told Prime Minister Boris Johnson that businesses fear “carnage” with the loss of staff to isolation, and people having to cancel social plans.

Some people have suggested they have deleted the app to avoid isolation requests for contacts with Covid-19 infections.

Changes to self-isolation rules in England will not come in until August 16.

Fully-vaccinated individuals and under-18s will no longer be told to stay at home if they have come into contact with a coronavirus case but will instead be advised to take a test.

People with confirmed cases of Covid-19 will still be told to self-isolate.