Eleven security screeners at the Qantas terminal of Perth Airport were ushered out of their jobs yesterday for wearing t-shirts with the printed message "Paid Less in the West."

Angered employees vow that they will stage a strike again to protest their employer's decision to lock out staff. The move has brought the number of screeners indefinitely out of the job to 25.

United Voice assistant secretary Pat O'Donnell said the incident happened yesterday during the 9:30 p.m. WST roster. Screeners also handed out stickers with the same message to travellers.

"If they think locking people out is deterring people, it's just making them more determined," Mr O'Donnell said.

He said around 40 screeners spent the last night protesting outside the terminal as part of their campaign.

The screeners are apparently complaining of low wages offered by their employer MSS Security. They protest that their salaries are lower compared with their interstate counterparts.

Strikes were held last week from Tuesday to Saturday, and union members are slated to meet on Monday to finalise if further industrial action will need to be taken.

The move to lock out staff, according to Mr. O'Donnel, reduced the screening points from two lines to one.

"If Qantas wants to not have lots of angry people outside their doorstep, they should be making sure there's fairness in their workplaces," he said.

Mr. O'Donnell added that they would keep on campaigning until an appropriate action to their protest has been taken.

Incidentally, the screeners' crisis coincided with problems of heavy fog since last night until this morning. Flights at the airport had been delayed with travellers getting frustrated by long queues, and announcements of flight rescheduling.

"Certainly, a bit of of chaos out there at the moment in all different ways," Mr O'Donnell said.

But a spokesperson of Qantas denied that the delays were caused by the current problem with screeners.

The airline representative said the flight problems were caused by the heavy fog, prompting the redirection of one flight and the cancellation of another.