Only fully-vaccinated football fans may be able to attend Premier League matches and other events with more than 20,000 spectators from October under Government plans.

Boris Johnson risks provoking further criticism from backbench Conservatives as ministers seek to extend the future use of vaccine passports from nightclubs to sporting stadiums.

Talks are in an early phase with the Premier League to discuss whether supporters who have not been double-jabbed could be barred from entry, the PA news agency understands.

The use of vaccine passports could also be extended to lower divisions and other sports in England as ministers seek to reduce the surge of Covid-19 cases as other restrictions are ended.

While no final decisions have been made, it is currently being discussed whether vaccine passports could be introduced for seated events with a capacity of 20,000 people and over.

In unseated events such as music gigs, where there are greater concerns about strangers mingling and spreading Covid-19, the threshold for their introduction could be as low as 5,000 attendees.

A Government source said: “It’s important that fans can continue to watch sporting events over the autumn, which is why we’re exploring the role vaccines might play in this.

“This will not only allow full capacity stadiums but has the added bonus of incentivising people of all ages to go and get their jab.”

One area still said to be under discussion is whether a recent negative test could allow entry to football matches, but their use has been ruled out for nightclubs.

The Prime Minister sparked a backlash when he made the nightclubs announcement on Monday, as he ended most of England’s remaining coronavirus restrictions and allowed the venues to reopen for the first time since March last year.

He said they could also be made a condition of entry for “other venues where large crowds gather”, adding: “Proof of a negative test will no longer be sufficient.”

Shadow sports secretary Jo Stevens said: “To insist on vaccine passports less than a month before the start of the season will cause major disruptions, especially for clubs at the lower end of the pyramid.

“Labour has been clear that the use of Covid vaccination status alone will exclude those who can’t be vaccinated or haven’t had the jab because of delays.

“Being double jabbed doesn’t prove you aren’t carrying the virus. Testing for access to venues would be more efficient.”

Making their use mandatory in the Premier League from October, however, would give time to phase in their use with the season starting on August 14.

The English Football League declined to comment, but it is understood contingency plans have been under discussion in case the Government advised the use of vaccine passports.

Chief scientific adviser Sir Patrick Vallance has warned nightclubs have the potential to cause “super spreading events”, but it is unclear to what extent what role football matches have in spreading Covid-19.

There were concerns, however, around fans travelling to London during Euro 2020.

Public Health Scotland figures showed there were nearly 1,300 Covid-19 cases linked to fans heading to the capital for events as Scotland faced England in the group stages.

That included 397 people who attended the clash in Wembley on June 18, according to the official figures.

A further 31,795 Covid-19 cases were reported in the UK on Saturday, as ministers sought to tackle the “pingdemic” causing staff shortages as workers are told to isolate over coronavirus contacts.

To facilitate the new isolation rules for some critical workers, the Government said daily testing for workplaces in the food supply chain was being extended to frontline emergency services and some transport workers.

An extra 200 testing sites are expected to open, but not until Monday at the earliest.

Reduced timetables were being introduced on railways across England after a spate of last-minute cancellations due to staff self-isolating.

The scale of the issue was shown by figures stating more than 600,000 people in England and Wales were told to quarantine by the NHS Covid-19 app in the week to July 14.

In the emergency measures to protect supplies, around 10,000 workers in the food sector were expected to be included in the scheme for fully vaccinated workers to be exempt from isolation if they test negative.

But figures in the food industry warned shortages on shelves could continue with more exemptions in the supply chain needed, such as in supermarkets.

Union leaders called for urgent clarification on exemptions for some transport workers amid warnings of confusion.

Rail, Maritime and Transport union general secretary Mick Lynch said: “It is ludicrous that this announcement has been made without any discussion with the unions or detailed briefing on who this scheme is supposed to cover and how it will be implemented.

“It leaves our members facing yet more uncertainty. I am seeking urgent clarification from both the employers and the Government before more damage is done.”

The hospitality industry has also warned of a “summer of venue closures” as staff are forced into isolation without any exemption.

There have been widespread calls for the Government to bring forward the wider relaxation of quarantine rules for the fully vaccinated from August 16.