The Australian Competition and Consumer Commission argues the term is misleading and deceptive for shoppers, and wants it banned, according to ABC.

The Chicken Meat Federation and one chicken meat company argue there's any confusion.

The Chicken Meat Federation filed papers in the Federal Court late last year, asking to be dismissed from the "free to roam" lawsuit.

The Federation argued the competition watchdog didn't have any evidence to prosecute its claim.

The ACCC's case centres around the space each chicken has in the shed, and if the chickens are therefore "free to roam".

In documents outlining its arguments, the ACCC alleges each chicken shed contains between 30,000 and 40,000 chickens, with an average space of less than an A4 sheet of paper each when the chickens are at a weight ready to slaughter.

The Chicken Meat Federation argues there no evidence to prove chickens aren't free to roam the shed.

A letter from the Chicken Meat Federation's lawyers to the ACCC's lawyers says the case is "deficient in failing to identify the connection between the average area per chicken in a shed (stocking density), and the area available for roaming in the entire shed."

The letter says, "There is no allegation, for example, that the chickens are inhibited in their movement by the proximity of other chickens".

The ACCC's lawyers disagree, saying, "We disagree with your contention that the ACCC does not have any evidence which directly addresses the space available for chickens to roam in sheds of Australian growers, nor evidence which establishes the connection between the average area per chicken in sheds and the space available for roaming."

The ACCC already has had a win against the "free to roam" term.

Chicken meat company La Ionica admitted its use of the term was deceptive and misleading.

The company was ordered to pay a $100,000 fine and agreed to remove all references to "free to roam" from its advertising.

In the judgements against La Ionica, the Honourable Justice Tracey had this to say about "free to roam."

"The representations conveyed the impression that the chickens had been raised in more spacious conditions that was in fact the case," the judgement reads.

"This was misleading. At some stages of the growth cycle an average of 18.19 meat chickens were confined within the space of a square metre inside the barn. Later in the cycle this density was reduced to 12.12 chickens per square metre but, by this time, the chickens had increased in size."

The Chicken Meat Federation and Baiada Poultry's day in court is March 13, where they'll battle it out with the ACCC before Justice Tracey.

Science is likely to play a part in the arguments, with animal welfare academics being asked to give expert evidence.

There's a lot at stake in the outcome.

In the judgement against La Ionica, Justice Tracey said the $100,000 fine was "towards the lower end of the proper range for contraventions of the relevant kind."

Then there's marketing and product packaging investment.

Baiada Poultry owns the Steggles brand of chicken products and supplies supermarkets with whole frozen chickens.

A quick visit to a supermarket shows the company uses the "free to roam" term heavily.