The Government has been accused of delaying "Freedom Day" after revealing that fully vaccinated people will still have to follow self-isolation rules until August 16.

Sajid Javid, the Health Secretary, announced on Tuesday that plans to allow Britons who had received both vaccine doses to take an optional PCR test if they came into close contact with a confirmed Covid case, rather than isolating for 10 days,  would not be introduced for five and a half weeks.

The delay comes despite Boris Johnson confirming on Monday that all legal Covid regulations are set to end on July 19.

It has dealt a blow to the hospitality and arts sectors, with warnings that venues and performances face being shut down when a single member of staff or crew tests positive for the virus.

There are also concerns about staff shortages in the NHS as a hospital was forced to cancel all non-urgent care after a large number of staff had to self-isolate.

Mr Javid warned on Tuesday that Covid cases could hit 100,000 a day, and analysis by the Adam Smith Institute showed rising infection rates could force up to 4.6 million people a week into self-isolation by the start of August.

Rolling seven-day case rate per 100k people on a logarithmic scale to highlight exponential growth, England

New figures released by the Department for Education showed the spiralling impact of self-isolation, with more than 640,000 pupils in England not in school due to Covid last week – up from around 384,000 the week before.

On Tuesday night, Sir Iain Duncan Smith, the former Tory leader, accused the Government of "splitting the message" and having "deliberately separated the good news from the bad".

He said delaying changes to the self-isolation regime until next month meant "Freedom Day is delayed" and "makes a mockery" of the idea that July 19 represented the end of restrictions.

"Why would you even go to a pub [after step four of the lifting of lockdown]? This makes it worse," he said. "I wouldn’t go to a pub that wasn’t still having six around a table and social distancing, otherwise you run the risk of everyone in the pub being pinged and locked down."  

The new system will still force anyone who tests positive for Covid to self-isolate regardless of their vaccination status, but will allow potentially millions of people who test negative after close contact with a confirmed case to escape being shut in their homes.

Karen Bradley, a former Cabinet minister and the Tory vice-chairman of the all-party parliamentary group on hospitality and tourism, called on ministers to rethink the timetable for lifting isolation requirements. She said: "Why on earth is it then [August 16] and not the same day that the rest of lockdown ends? It just doesn’t seem to make any sense."

Sport will also continue to face chaos as a result of the continuation of the rules. It was announced on Tuesday that a new England cricket squad would be selected to play Pakistan after the initial team was ordered to self-isolate in the wake of three players and four backroom staff testing positive.

Sir Roger Gale, another Tory vice-chairman of the all-party parliamentary group on hospitality and tourism, said resorting to the selection of an entirely different national team seemed unnecessary.

He likened the Government retaining self-isolation rules after lifting all other measures on July 19 as "taking the brakes off with one hand, then slamming brakes on with our feet", adding: "It doesn’t make any sense."

Businesses warned the rules could force them to close.

Kate Nicholls, the chief executive of UKHospitality, said she believed as many as a third of workers in the industry may either be isolating or off work because of the present system. She said it was causing "carnage", adding that the delay in moving to a test to release system could harm the sector’s recovery.

Emma McClarkin, the chief executive of the British Pub and Beer Association, also called for the rules to change on July 19, warning of "great confusion among our customers and staff".

The rules will also affect theatres. It emerged on Tuesday that the hit West End revival of the musical Hairspray has had to cancel performances for 10 days this month after a single member of the production team tested positive for Covid.

Julian Bird, the chief executive of the Society of London and UK Theatre, said Mr Javid’s announcement meant "more theatres and shows will be forced to close just as they are allowed to open in full".

He added that "given the strictly controlled working environment under which theatres are already operating", a testing regime to replace the current system was needed no later than July 19.

The health sector has also been hit by isolation rules, with Raigmore Hospital in Inverness forced to cancel non-urgent care as it declared a "code black" incident as a result of a large number of staff having to self-isolate.

Prof Keith Neal, emeritus professor of the epidemiology of infectious diseases at the University of Nottingham, said forcing double-vaccinated contacts to isolate until mid-August could harm patients.

"The numbers of staff isolating will be having a knock-on effects on care for cancer and other serious conditions," he said. "The big question is why not implement the change now – the science won’t change in the next 41 days. Other countries have been doing this for months."  

How many people have been vaccinated?

In the Commons, Mr Javid signalled that the reason for waiting until August 16 was that "even more people will have the protection of both doses" and that "modelling suggests the risk from the virus will be even lower".

It is understood government modelling shows that the third wave of Covid cases will peak in mid-August – another reason ministers decided to wait to change the self-isolation rules.

A government source hit back against the accusation that "Freedom Day" had been postponed, saying: "July 19 is a pretty huge step in terms of all legal restrictions falling away."

The source added that self-isolation was "an incredibly important tool in preventing the spread of the virus" and insisted it was right to be "cautious".