One journalist spent 12 days working inside the 2 Sisters portioning and packing plant in West Bromwich, while the other was employed for three days at this slaughtering facility in the village of Willand, about 20 miles north of Exeter.

According to The Guardian, at Willand, chickens, still living but seemingly catatonic, arrive packed into green and yellow plastic latticed crates on the back of lorries, where they are routinely comforted by animal rights activists, wishing to say goodbye to "5,000 lost chicken souls".

You can view the full article by The Guardian by clicking here.

2 Sisters' response to the Guardian/ITV undercover investigation

In light of the allegations, 2 Sisters Food Group issued a statement yesterday, stating: "We have been made aware of several broad allegations made by The Guardian/ITV in relation to inappropriate procedures, food safety and hygiene issues at two of our poultry processing facilities.

"We view these allegations extremely seriously.

"However, we have not been given the time or the detailed evidence to conduct any thorough investigations to establish the facts, which makes a fulsome response very difficult.

"What we can confirm is that hygiene and food safety will always be the number one priority within the business, and they remain at its very core.

"We also successfully operate in one of the most tightly-controlled and highly regulated food sectors in the world.

"We are subject to multiple and frequent unannounced audits from the FSA, BRC, Red Tractor, independent auditors as well as our customers. By example, our facility in the West Midlands under investigation received nine audits (five unannounced) in the months of July and August alone.

"However, we are never complacent and remain committed to continually improving our processes and procedures.

"If, on presentation of further evidence, it comes to light any verifiable transgressions have been made at any of our sites, we will leave no stone unturned in investigating and remedying the situation immediately."