John Hopoate is pushing ahead with a legal fight to revive his Manly coaching career despite stubborn opposition from the NRL.

Hopoate will take his dispute over the NRL’s refusal to register him as the Sea Eagles’ under-18s coach to mediation, his lawyer confirmed on Wednesday.

Barrister Julieanne Levick said they had asked the NRL to the negotiating table and if that failed they would take their case to the Supreme Court.

“We’ve invited them to come to the table and mediate,” Levick told AAP.

“If not, without further notice, we’ll begin Supreme Court proceedings … we’ll have a Supreme Court judge make a call in relation to this jurisdictional issue.”

The club earlier this week agreed to stand down the 42-year-old but he has vowed to fight on.

The Sea Eagles and NSWRL have been at loggerheads for months after the controversial former player was appointed to take charge of the club’s SG Ball side.

The NRL insist that Hopoate is not a “fit and proper person” to be heading up the Sea Eagles’ elite junior team.

The Sea Eagles were last month urged to stand down Hopoate by the NSW organised crime squad out of concerns he was unfit to mentor young players.

The most suspended player in the history of the NRL has vowed to take any sanction to the NSW Supreme Court, claiming it’s the NSWRL that has jurisdiction over the SG Ball competition, not the NRL.

It is the NSWRL’s position that Hopoate has met the various criteria to qualify as a coach at a junior level.

Hopoate was a bystander when the side trained on Tuesday.

NRL head of football Todd Greenberg on Tuesday declared the matter “closed” and indicated the governing body would not enter into any further discussions with Hopoate.

Meanwhile Sonny Bill Williams has urged the NRL to allow Hopoate to continue his coaching career.

Two-time premiership winner Williams believes Hopoate has paid for his previous indiscretions and should be allowed to mentor the NRL’s rising stars.

“Let the past be the past, Seems like ‘Hoppa’ wants to use it in a positive way and we need more islander coaches coming through the grades.” Williams wrote on Twitter.

Williams has turned around his public image since emerging as one of the NRL’s most reviled figures when he walked out on Canterbury in 2008.

His positive influence on younger players during his return to the NRL with Sydney Roosters in 2013 and 2014 is credited as a significant factor in the club’s 13th premiership success.