Almost 2,000 people in Wandsworth have been told to self-isolate by NHS Test and Trace after being in contact with someone who tested positive for Covid, but more than 400 can’t be reached.

During the week  to July 7, a total of 1,814 people were told to stay at home – the highest number since January 20, according to latest data from the Department for Health and Social Care.

A record number of Wandsworth residents were self-isolating in January just three weeks after the country went into a third lockdown.

Those in self-isolation have been told by contact tracers to pass on the details of anyone they were close to 48 hours before their symptoms began to show.

Some 2,254 people were close to a Covid-positive person in Wandsworth in the week to July 7 but 440 of them could not be reached by Test and Trace.

These figures do not include people who have been told to isolate in settings such as schools and prisons.

More than 160,000 Covid cases in England logged by Track and Trace between July 1 and 7, with a further 381,000 coming in close contact to a Covid-positive person – again, the highest number since January 20.

The latest government data for Wandsworth shows there were 262 Covid cases in the borough on July 19, but no deaths.

If someone is alerted by the Covid app of being near a positive case, it is recommended but not mandatory to isolate. But if you are contacted by Test and Trace, you have a legal duty to self-isolate.

Unite the union has said hundreds of employees are off work at several major factory sites, mainly in the automotive sector, after being “pinged” by the NHS app.