The criminality involved in Eddie Obeid's latest conviction exceeded that of the case in which the NSW Labor powerbroker served three years behind bars, a judge has been told.

The 77-year-old, his 52-year-old son Moses and 72-year-old fellow former minister Ian Macdonald were found guilty in July of conspiring for Macdonald to engage in misconduct as a minister between 2007 and 2009.

The men, whose bail was continued after verdict, faced a sentence hearing in the NSW Supreme Court before Justice Elizabeth Fullerton on Wednesday.

Their conspiracy related to the then mining minister's actions in establishing and granting a coal exploration licence over the Obeids' family property at Mount Penny, in the Bylong Valley near Mudgee, for the family's financial benefit.

The misconduct led to a $30 million windfall for the Obeid family.

Prosecutor Sophie Callan SC on Wednesday referred to the five-year jail term imposed on Eddie Obeid by another judge for misconduct in public office.

His parole expires in December after he was released in 2019, after serving the minimum three-year term.

The misconduct involved lobbying a public servant to secure lease renewals for two lucrative Circular Quay businesses in 2008 without revealing his family's financial interests in the outlets.

Ms Callan submitted that both the seriousness and criminality of the conspiracy matter "exceeds in a material way" the type of misconduct for which he was previously sentenced.

"The Crown contends the objective seriousness was at the high end because it included a breach of trust by a minister," she said.

But she accepted that Justice Fullerton was in "relatively uncharted territory" for sentencing due to the lack of previous comparable cases.

She also agreed the judge should proceed to sentence each of offenders on the basis that the maximum term available was in excess of seven years.

Voluminous material was tendered to the judge including character references, reports on the men's medical problems and the issue of COVID-19 in jails.

Mention was made of Macdonald's chronic conditions of incontinence and constipation, which one expert said would benefit from a procedure which the practitioner would undertake in the community.

But Ms Callan said the need for that surgery would be a matter taken up by the Justice Health network.

She did accept that the ages and health of the two older offenders were matters which could be taken into account.

Barristers for the three men will make their submissions on Thursday.