More than 600,000 people were told to self-isolate after coming into contact with a Covid case in the week until July 14, sparking train cancellations and food shortages.
On Thursday, the government said supermarket depot staff and suppliers at 500 sites will be permitted to skip quarantine if they test negative for Covid.
Police, fire, Border Force, transport and freight staff will also now be able to join a daily workplace test scheme, whether they are vaccinated or not.
Home Secretary Priti Patel said: “Daily testing will keep our frontline teams safe while they continue to serve the public and communities across our country.”
From 16 August anyone in England who is fully vaccinated - and unvaccinated under-18s - will be able to take daily tests instead of self-isolating. Similar rules come into force in Scotland from 9 August - and in Wales from 7 August.
But Boris Johnson is facing mounting calls from businesses to immediately end quarantine for anyone who has had both doses a Covid vaccine.
London Mayor Sadiq Khan teamed up with industry bodies including UK Hospitality and the London Chamber of Commerce and Industry and the capital’s branch of the Federation of Small Businesses to demand the PM relax the rules.
Amid rising coronavirus cases, they warned that staff shortages in different industries are being “exacerbated” and leading to temporary closure as a result ofthe “pingdemic”.
“The summer months are crucial for many businesses’ recovery and their ability to recover must not be put in jeopardy,” they said.
“We are therefore calling on you to ensure that the necessary testing is in place to enable people who have been double vaccinated for longer than two weeks and pinged by the NHS Covid app, to immediately return to work, following a negative PCR test, rather than having to self-isolate.”