Animal welfare campaigners claim to have uncovered "shocking conditions" at a huge egg farm housing around 64,000 birds.
Investigators from the pressure group Animal Aid say they recorded secret footage during a visit to Combwell Farm near Goudhurst which they allege reveals serious cause for concern over the conditions in which the hens are kept.
Animal Aid secret footage from egg farm
However the farm's operator, Fridays Ltd, has hit back at what it describes as made by a "group of anti-farming extremists" who it says could have put the health of the flock at risk by entering the site.
Graham Fuller, production manager at the firm, said: "If, as they claim, they did break into one of our hen-houses then they have breached bio-hazard security measures and put the health of the birds at risk.
"Their actions have potentially exposed the hens to avian influenza at a time when the risk level has been raised to high. If they have been infected then the Government will require the whole flock to be slaughtered.
"It was also a totally pointless exercise as we have an open-door policy and would have happily shown them round - with proper bio-security measures in place - as we have other organisations as well as local residents and councillors.
"Furthermore, we strongly refute the misleading impression given by the pictures that the hens are not properly cared for. While we cannot yet confirm whether the photos are from one of our sites, we do not recognise them as representative of the operation of our farms."
Combwell Farm produces around a million eggs weekly to sell to the free-range market, however critics have attacked conditions as "high-rise urban living for hens" and questioned whether eggs produced this way should be labelled as free-range.
Upon entering the shed, Animal Aid investigators describe being hit by the strong stench of ammonia in the heavy, dusty and stifling air. Combined with the noise of thousands of hens, they described the conditions as "absolutely overwhelming and oppressive".
Animal Aid campaign manager Tor Bailey said: "This is intensive farming in a different guise, with the chickens living in incredibly cramped conditions with limited access to the outside.
"On our visit the weather was not too adverse but there were very few hens out on the range, compared to the many thousands who remained inside.
"Animal Aid feels that people need to see what happens in the vast crowded sheds that are conveniently located largely out of sight and therefore out of mind for most people and question whether this is really a progressive, animal friendly solution, or it's just green-washing of an inherently cruel industry."
Cranbrook-based Fridays, which employs almost 300 people in the county, is set to apply for permission to build its new Wealden Woods farm south of Maidstone.
It would comprise of three hen houses, each capable of accommodating up to 64,000 chickens and producing some 60 million free range eggs a year.
Mr Fuller said: "This is not the first time Animal Aid has sought to discredit responsible livestock farmers. It is clear their agenda is not about welfare but is part of a campaign by militant vegans to disrupt animal-based food production.
"Demand for free-range eggs, produced in a high quality way, continues to rise and we won't allow these extremists to deter us from meeting the needs of the public. If they succeed in shutting down UK egg production it will simply open the door to eggs from countries where welfare standards are far lower.
"Our plans at Wealden Woods continue to progress well. We are currently revising the original layout in light of feedback from local councillors and residents, including moving one of the units further from the nearest residential properties. We hope to submit a planning application to Maidstone Borough Council in the near future."
A spokesman for the Government's Animal and Plant Health Agency said: "There is specific and strictly enforced legislation to protect the welfare of all poultry, which every operational farm must comply with.
"We take all potential breaches of animal welfare laws very seriously and investigate all allegations. Where welfare regulations are breached, appropriate action is always taken."