The number of people in Islington "pinged" and told to self isolate in Islington in the week to July 14 was 4,549.

This is the highest number so far for the borough, and up on 4,097 the previous week. As recently as the end of May the figures were only in the double digits.

Since the NHS Test and Trace Covid-19 app was introduced in September, a total of 27,372 people have been pinged.

At the same time, the number of people checking in at venues is falling, with 55,205 check-ins in Islington in the week ending July 14, compared to a peak of 89,943 at the beginning of June.

A No 10 spokesperson said: “Given the risk of having and spreading the virus when people have been in contact with someone with Covid, it is crucial people isolate when they are told to do so, either by NHS Test and Trace or by the NHS Covid app.

“Businesses should be supporting employees to isolate, they should not be encouraging them to break isolation.”

Across sectors, staffing shortages are being experienced and emergency measures introduced by the government will see thousands of workers at up to 500 critical sites potentially avoid the need to self-isolate if identified as a contact of a coronavirus case.