POSTAL workers locked in an industrial dispute with their employer will deliver unstamped letters until Christmas Eve.

The Australia Post employees are seeking a new workplace agreement which protects penalty shifts, rosters and take-home pay.

They also want an improvement in job safety conditions.

After negotiations with the company over the new agreement stalled earlier this month, about 32,000 posties vowed to deliver mail posted in street boxes without a stamp.

The industrial action began today and will last until Christmas Eve, but postal workers couldn't guarantee unstamped mail would reach its destination.

Communications Electrical Plumbing Union spokesman Jim Metcher said Australia Post had cut 225 jobs in the past three months and those still employed had been waiting three years for a new wage deal.

"This action ... is about sending Australia Post the message," he told ABC Radio today.

"The message is that postal workers have waited long enough for a new wage deal and they want one now."