SHOPPERS have been told not panic over supermarket shortages as retail bosses continue to raise concerns over the so-called "pingdemic".

Lidl said the number of employees self-isolating is "starting to have an impact on our operations", while the Co-op said it was being affected "by some patchy disruption to our deliveries and store operations".

Iceland's managing director, Richard Walker, said the supermarket was having to hire 2,000 temporary workers to prepare for "the exponential rise in pinging".

But Mr Walker told BBC Radio 4's Today programme that the "dramatic pictures that you might have seen in the media" of empty shelves "are isolated incidents and not widespread".

He said staff absence rates are now double the usual number, with the figure rising 50 per cent "week on week" due to people being told to self-isolate by the NHS app.

Mr Walker said: "We've now got over 1,000 staff off, who've been pinged. That's double the normal rates, and it's rising at 50% week on week.

"Our big concern is that we've kept all of our shops open throughout the pandemic, but now we have had to close one or two shops and reduce hours in others.

"But that could get a lot worse a lot quicker, unless the country's system is sorted out."

Mr Walker urged shoppers not to panic buy, saying: "There is certainly no problem with supply of stock.

"Panic-buying is only an option for those who can afford it and it often means that others go without."

Elsewhere, sandwich chain Pret A Manger has temporarily closed 17 shops due to staff being forced to self-isolate.

UK Business Secretary Kwasi Kwarteng said Mr Walker "was right to say shoppers shouldn't be panicking".

He said a "very narrow" list of sectors whose workers will be exempt from isolation rules in England will be published later today.

Retailers warned the situation around alerts from the NHS app is "untenable" and requires an urgent rule change.

Downing Street this week suggested that there would be no list of sectors whose fully-vaccinated workers could face loosened isolation restrictions to prevent staff shortages.

But in the face of mounting pressure, Mr Kwarteng said: "We're looking at different sectors and we will be publishing today the sectors that will be affected."

He said he would not "pre-empt" the list when asked if the food industry would be on it, amid pleas from bosses to prevent major staff shortages as Covid-19 cases soar.

But he told BBC Breakfast the list would be "very narrow, simply because we don't want to get into a huge debate about who is exempt".

The British Retail Consortium (BRC) has urged ministers to "act fast" to allow fully-vaccinated workers, or those who test negative, to be exempt from isolation after a "ping".

BRC chief executive Helen Dickinson warned stores are closing, hours are being reduced and consumers are facing reduced choice.

"I think what the most important thing for Government to do is to recognise that the current situation is untenable," she told BBC Breakfast.

Boris Johnson announced the plan for a "small number" of critical workers to be able to continue their roles despite being pinged as he scrapped most of England's Covid restrictions on Monday.

On Tuesday, the Prime Minister's official spokesman said: "It's not a blanket exemption and my understanding is we're not going to be producing a list covering individual sectors, these business-critical areas will be able to apply for exemptions to their host departments."

But the UK Government appears to have changed course on that amid mounting criticism.

A lorry driver shortage was putting increased pressure on the country's grocery supply chain and empty shelves were witnessed in some supermarkets across the country.

Mr 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.

Bidfood chief executive Andrew Selley defended his approach for delivery drivers to continue working if they have negative results as "appropriate and safe" for the "critical workers".

"If they are pinged we ask them to take a PCR test, if that's positive then clearly they'll isolate but if it's negative we ask them to come back to work and we have a process of doing lateral flow tests daily away from their workplace and if that's negative they can proceed with their work," he told Today.

But Mr Kwarteng responded: "I would stick to the rules, which are very clear, which say that if you are pinged you should self-isolate."