RISDON Prison guards should know today if they are going back to work.

On Monday 40 workers were stood down without pay for refusing to work under new conditions which they said put their safety at risk.

Unions, prison workers and staff from the Department of Justice gave evidence at a hearing in the Industrial Commission for the second day yesterday.

Liquor Hospitality and Miscellaneous Workers Union state secretary Helen Gibbons said all evidence had been tendered and an answer was expected today.

Ms Gibbons said she would go back to members to work out the next plan of attack if workers were asked to go back to work under the new conditions originally scheduled to start on Monday.

Prison Action Reform spokesman and Mercury columnist Greg Barns said today's decision would be historic.

"Nick McKim is the first minister in Australia who understands the humane treatment of prisoners equals a better outcome," Mr Barns said.

"If the union wins this battle it will be a once in a lifetime opportunity lost."

Opposition corrections spokeswoman Vanessa Goodwin said yesterday Mr McKim should be working more co-operatively with the unions.

"He has taken a confrontational style to this and obviously the delay in resolving this matter has implications for this prison with prisoners in lockdown for an extended period of time," she said.

Visitation and non-emergency phone calls are unavailable under full lockdown conditions while the prison runs with limited staff.