Influential union bosses have criticised the NSW Labor Party as "rotting from its core" in a call for sweeping cultural reform to its leadership and base.

AMWU NSW leader Steve Murphy. Credit:Wolter Peeters

In a submission to the NSW ALP's governance review led by former attorney-general Michael Lavarch, the Australian Manufacturing Workers Union NSW branch said its faith in the party was shattered and allegations of corruption were part of a cultural problem.

"This is not the case of one, or even a couple of bad apples," the submission says. "This is a case of the entire cart rotting from its core.

"The current state of affairs within the New South Wales ALP shatters the AMWU's faith in the structures that are established to respond to crisis or govern with any level of transparency.