The first test case relating to 19 dairy farmers accused of using the services of an unlicensed labour provider will go to full trial this autumn.
District judge Simon Cooper confirmed the trial would start on 24 October.
It is expected to last up to five days, he told a court hearing in Swindon on Monday (11 July).
Oxfordshire farmer Brian Barnett was selected as the test case because his name was first on the alphabetical list of defendants.
The 19 defendants are charged with using the services of Wiltshire-based Marden Management, an unlicensed labour provider.
They include some of the biggest names in dairy farming, including NFU vice-president Gwyn Jones and Wills Bros of Cornwall.
All defendants have pleaded not guilty, with the exception of the University of Reading, which has not entered a plea.
The case is being brought by DEFRA following a lengthy investigation by the Gangmasters Licensing Authority (GLA).
Judge Cooper said hearing a single test case in full may serve to clarify legal issues for the other 18 defendants.
In the meantime, he ordered DEFRA to hand over all the necessary documents to the defendants’ legal representatives by 1 August.
This includes all correspondence between DEFRA, the GLA and Marden Management.
Marden Management supplied British and overseas agricultural workers to UK dairy farms – including about 60 Filipino migrant workers.
But the firm was unlicensed and it is a criminal offence to employ farm workers supplied by an unlicensed labour provider.
GLA officials passed their findings to the prosecutor within DEFRA last year.
At the time, Marden Management director Chris Blakeney said his company had made an honest mistake. He believed Marden did not need a licence because it supplied qualified and experienced dairy workers, rather than unskilled labourers.
It is unclear at this stage whether Marden Management has been charged.