VANCOUVER -- The authority in charge of Vancouver-area ports is responding to unionized truckers' threat of a second strike, saying it is already taking steps to enforce minimum pay rates.

Port Metro Vancouver said it has created a complaint phone line allowing truckers to report companies allegedly underpaying their workers.

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

Parker-Jervis said the process takes several weeks on average.

"The process as part of the audit program for looking into those reports will take some time so we are asking for patience," he said.

But Gavin McGarrigle of Unifor has said unionized truckers are frustrated the federal and provincial governments still have not delivered on a promise to establish and enforce a minimum rate of pay for all drivers.

"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 said this is allowing some companies to underpay drivers.

He said if government does not enforce minimum pay rates for all drivers soon, he said more than 400 unionized truckers will go on strike.

"They're not whispering -- they're starting to yell," said McGarrigle, referring 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.

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