A food distribution firm struggling with staff shortages is advising workers who are pinged by the NHS app to take tests and continue working, in breach of 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” because they are “critical workers”.

He said the firm, whose customers include hospitals, has heard no information about how to apply for an exemption for some fully-vaccinated staff to avoid quarantine under new plans to ease the “pingdemic”.

Amid a “real challenge” in completing orders on time, he said workers are being asked to follow a testing regime if they receive an alert from the app as a close contact.

We operate in Covid-safe workplaces and we’re absolutely key workers in terms of the supply chain to hospitals, care homes, prisons, and therefore it’s important for us to be able to keep offering that service to our customers

“We know that they’re critical workers as part of the food supply chain, so if people are obviously positive or contacted by Test and Trace then they will have to isolate,” he told BBC Radio 4’s Today programme.

“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.”

Ministers have confused the rules this week, but, as they stand, isolating for 10 days after an alert from the app is the official advice from the Government, but it is not a legal obligation like if contacted by Test and Trace.

Told his testing programme is contrary to Government advice, Mr Selley said: “We think that’s appropriate and safe. The ping is advisory.

“We operate in Covid-safe workplaces and we’re absolutely key workers in terms of the supply chain to hospitals, care homes, prisons, and therefore it’s important for us to be able to keep offering that service to our customers.”

Mr Selley said 100 staff from around 20 depots across the country were off isolating on Wednesday, presenting a “real challenge” with deliveries arriving late, or even the next day.

Boris Johnson announced an exemption for a “very small number of named critical workers” who have received both jabs, ahead of a greater easing of the rules for the fully-vaccinated on August 16.

But the Prime Minister has faced pressure to go further as businesses struggle with shortages as coronavirus cases soar.

Asked about the current exemption, Mr Selley said: “We’ve heard talk of the Government system to apply but there’s no detail as to how to apply, so it’s touted as something that’s out there, but we’ve heard nothing in terms of how one could apply for that status.”

This week business minister Paul Scully said it is a decision for individuals and employers whether they should isolate after a “ping” from the app.

But he was quickly contradicted by Downing Street, which insisted it is “crucial” for people to self-isolate after receiving an alert from the NHS Covid-19 app.

On Thursday, Business Secretary Kwasi Kwarteng also contradicted his junior minister, telling BBC Breakfast: “The rule is very clear, we should self-isolate. It’s as simple as that. If you are pinged, you should self-isolate.”

He warned firms not to dismiss the isolation advice.

Asked if Bidfood’s approach is safe and appropriate, Mr Kwarteng told BBC Radio 4’s Today programme: “No, I would stick to the rules which are very clear which say if you are pinged you should self-isolate.”