Mr Parsloe laughed off this suggestion.
"They (PortPro) are so insignificant with their numbers I'm not concerned. If there were people leaving us and going to them I would be a bit concerned but that's not happening."
Despite PortPro asserting it was independent of Ports of Auckland, Mr Parsloe was adamant they were working together.
"Just take the name of it: PortPro. They're pro-port. And then take a look at what the employer is saying: that they got everything they wanted out of the negotiations so what does that tell you other than capitulation?"
Mr Parsloe said the formation of the union went against good-faith bargaining.
PortPro was set up recently by former Maritime Union member Grant Lane, who wanted to offer non-striking stevedores an alternative.
He has previously said PortPro was "totally independent" of the company, and had been set up to protect the interests of the non-striking workers against any renewed attempt to contract out waterfront work, which has been on hold since March under an Employment Court-approved agreement with the Maritime Union after a summer of industrial turmoil.