A union has accused Australia Post of putting the security of mail across Victoria at risk because of its decision not to empty most street boxes over the Labour Day long weekend.
Communication Workers Union state secretary Joan Doyle said that Australia Post management had decided to leave mail in the red street post boxes until Monday evening, instead of doing a normal Sunday clearance this weekend.
"We are very concerned about the security of the community's mail given that street post boxes are often vandalised with mail set alight or damaged by substances," Ms Doyle said.
"Most mail will be sitting there from 6pm on Friday until 6pm on Monday," she said.
Ms Doyle said that Australia Post drivers were also upset about losing their Sunday rosters because it meant they would miss out on overtime.
"Postal workers are angry at Australia Post's decision to cancel their usual Sunday rosters in transport hubs in Victoria this weekend," Ms Doyle said.
The union said it was a case of Australia Post "penny pinching at its worst".
"We are also dismayed that for the sake of some small savings Australia Post is prepared to delay mail destined for other states that are open for business and to let the unknowing public wait for their mail from Victoria," Ms Doyle said.
Australia Post confirmed that only some red street boxes would be cleared on the Sunday evening.
But it denied union allegations that mail left in boxes would be at risk.
"As mail volumes are traditionally light over a long weekend, Australia Post will do selected street posting box clearances in metropolitan Melbourne on Sunday and a full clearance on Monday," a spokesman said.
"This will only affect street posting boxes that have light usage.
"Australia Post assures customers this will not adversely affect service standards."
Australia Post said that drivers affected by the change were consulted.
"It will not affect normal duties, but will reduce the amount of overtime on the Sunday," a spokesman said.