Photo: © 2009  Jupiter Images/Jeremy Woodhouse

Workers at Australia Post are considering a strike in a bid to protect full-time job security and penalty shifts.

Postal workers will decide on Friday morning whether to go ahead with industrial action that includes a ban on checking if letters and cards have been stamped.

With approximately 70 million cards sent by Australians each Christmas, that could mean a loss of $35 million in revenue for the post office.

"Our members want a better enterprise agreement to protect their jobs, safety and pay," says union spokesman, Ed Husic.

He adds that Australia Post has contingency plans in place to cause minimal inconveniences to the public if a strike were to go ahead.