Several hundred unionized truck drivers servicing Port Metro Vancouver container terminals are threatening to strike again if officials don't crack down on companies that are undercutting the minimum rates set to end the last strike.

But Port Metro Vancouver says it is already taking steps to enforce minimum pay rates by creating a complaint phone line and is asking truckers to be patient

Port spokesperson John Parker-Jervis says the province investigates the complaints, and then makes recommendations on penalties, which can be as severe as banning companies from the ports.

"We have seen a lot of progress and a lot of work happening," says Parker-Jervis, "We're certainly encouraging truckers to use the line and to report any instances where they do feel rates aren't being paid."

Since the line's inception, it's received more than 100 calls, but Parker-Jervis says the process takes several weeks on average.

"That audit process does take a bit of time, so we certainly are appreciative of patience within the industry as that process goes through."

Truckers frustrated by enforcement delays

But the B.C. director of Unifor, Gavin McGarrigle, says unionized truckers are frustrated by the slow progress of the federal and provincial governments to enforce a minimum rate of pay for all drivers.

Striking container truck drivers at Commissioner Gate

Unionized container truck drivers protest outside the Commissioner Street entrance to Port Metro's Vancouver facilities earlier this year. (Christer Waara/CBC)

"They're saying they're going to," said McGarrigle. "But they're certainly not doing it in the time frame that was set out."

McGarrigle says this is allowing some companies to underpay drivers and, if the governments do not enforce minimum pay rates for all drivers soon, more than 400 unionized truckers will go on strike.

"They're not whispering — they're starting to yell," says McGarrigle, referring to truckers' complaints. "I would say the situation is almost at a boiling point."

More than 1,000 non-unionized truckers went on strike in February and 250 of their union counterparts joined them in March, crippling operations at Vancouver-area ports for weeks.

But a deal was reached at the end of March, and drivers went back to work. The dispute focused on pay, unpaid time spent at the port waiting for cargo, and allegations some companies underpaid drivers.

Parker-Jervis says 12 of 14 job action plan commitments have been met since March.

Neither provincial or federal levels of government would immediately comment on the union's threat.