Dozens of advocates are set to represent Scottish prisoners seeking government damages over slopping out.
The government faces hundreds of claims for compensation
Inmates from Peterhead Prison in Aberdeenshire will seek compensation at a single hearing at the Court of Session in Edinburgh next week.
It is thought the 9 March hearing could be a legal landmark due to the 42 advocates involved.
Last month the Scottish Executive lost an appeal over a slopping out claim made by a former prisoner.
Armed robber Robert Napier was awarded £2,450 last April when he complained he had suffered an outbreak of eczema after having to slop out at Barlinnie Prison in Glasgow.
It was thought the case would open the floodgates for hundreds of similar claims and the final compensation bill could amount to millions.
A week after the Peterhead hearing, 30 advocates are due to represent prisoners from Edinburgh Prison in a separate hearing at the same court.
Solicitor Tony Kelly, who is based in Coatbridge, North Lanarkshire, said he has more than 700 clients with more than 200 cases already with the sheriff courts and 150 with the Court of Session.
Mr Kelly said: "The government were put on notice throughout the 1990s of the unacceptability of these conditions and the executive should have ordered their affairs post-devolution.
"The executive's liability commenced in 1999 but they have never given a commitment to abolish slopping out."
The Scottish Prison Service (SPS) maintained the Napier case should not have triggered an avalanche of similar claims.
A spokeswoman said: "It has been clear from the outset that the Napier case was not a test case.
"It relates to the conditions in which a prisoner was detained in Barlinnie in 2001 and the particular effect of those conditions on the prisoner's health.
"We are still considering the appeal judgement delivered last month.
"The SPS is aware of a large number of slopping out cases before the courts and is keen to find a way to make the process more manageable."