Nelson MP Nick Smith says a flotilla of more than 40 boats that took their protest against expanding salmon farms to the waters of the Marlborough Sounds won't make a difference.
King Salmon is proposing the development of eight new sites in the Sounds.
The flotilla, organised by the group Guardians of the Sounds, sailed to the King Salmon marine farm at Ruakaka Bay on Saturday.
The group says the fish farm expansion would trigger a gold rush of applications that would be catastrophic for the Sounds, and says locals are also worried about pollution of the waters.
Dr Smith says it was inappropriate to be expressing a view when evidence is still being heard by the Environmental Protection Authority.
"In some ways it's not much more useful than a lynch mob outside a criminal court," he says.
He says the judge and board can consider only information before the board, rather than any outside activities, such as the protest.