Hundreds more people were told to self-isolate by Test and Trace in Thurrock in the latest week, figures show.

Department for Health and Social Care data shows 674 people were told to self-isolate after being in contact with someone who tested positive for Covid-19 in the week to July 14 – the latest available data.

This was up from 387 the week before, and means 1,061 people have been told to isolate in the latest 14 days alone.

Contact tracers ask new patients to give details for anyone they were in close contact with in the 48 hours before their symptoms started.

The figures show 738 people who came into close contact with someone who tested positive for Covid-19 in Thurrock were transferred to Test and Trace in the week to July 14.

It means 64 contacts were not reached by the service. The figures do not include those told to isolate in specific settings such as schools and prisons.

Across England, more than 223,000 cases were transferred to the contact tracing system between July 8 and 14, with 475,500 people identified as coming into close contact with someone who had tested positive.

The number of close contacts identified is now the highest observed since the week ending January 20.

Separate figures also show that 618,903 alerts were sent to users of the NHS Covid-19 app in England and Wales telling them to self-isolate.

Isolation is recommended but not mandatory, if someone is alerted by the app, while those contacted by Test and Trace have a legal duty to self-isolate.

The Government has come under fire after businesses revealed they were struggling to cope with increasing numbers of people being "pinged" by the app.

Pictures of empty supermarket shelves were widely shared online, suggesting the app was causing disruption to the sector.

Richard Walker, managing director of supermarket giant Iceland, said the firm was having to hire 2,000 temporary workers to prepare for “the exponential rise in pinging”.

The British Retail Consortium has urged ministers to “act fast” to allow fully-vaccinated workers, or those who test negative, to be exempt from isolation if notified by the Covid-19 app.

The Government will introduce a wider relaxation for all double-jabbed individuals but that will not come until August 16 – a month after most coronavirus laws ended.

That date “feels a long time away”, however, BRC chief executive Helen Dickinson said, as she warned stores are closing, hours are being reduced and consumers are facing reduced choice.

Business Minister Kwasi Kwarteng had to tell businesses to “stick to the rules” after a food distribution company struggling with staff shortages advised workers who are pinged by the NHS app to take tests and continue working, in breach of the Government advice.

He said: “I would stick to the rules, which are very clear, which say that if you are pinged you should self-isolate.”

The Government was due to publish a list of sectors exempt from isolation on Thursday, July 22.