More protest actions continue to build up at Perth Airport as security screeners pursue their demand for better wages.

On Tuesday morning, security screeners refused to do routine bag inspections, laptop and aerosol tests. It happened at the Qantas Terminal during one of the busiest hours for mining centres' incoming and outgoing flights.

A Qantas spokeswoman denied that the industrial action affected operations of the terminal. She said they had prepared in advance for such occurrence by putting contingency plans in place.

United Voice Assistant Secretary Pat O'Donell, meanwhile, reiterated full support for the workers' grievances. He said employees are only appealing for a just and fair compensation from their employer MSS Security.

Workers are apparently complaining of significantly lower wages compared with their interstate counterparts. O'Donell added that MSS has since discharged at least 20 workers just to force their wage offer.

"All they (workers) are asking for is parity with what MSS has just offered its Melbourne workforce," Mr. O'Donell said.

This means an increase of 12 percent in workers' basic pay at 4.3 percent, 3.85 percent and 3.85 percent spread over the next three years. Also included in their appeal are improvements in the weekend rates and morning shift allowances.

Just last week, around 40 screeners protested outside the terminal following the lock out of eleven security screeners who wore t-shirts with printed message "Paid Less In The West."

Strikes were also held last week from Tuesday to Saturday, and union members vowed to continue staging industrial actions until their demands are appropriately addressed.