More than 30 Ballarat posties and eight Australia Post truck drivers walked off the job yesterday afternoon in a bid for better pay and conditions, with a small contingent manning a union picket line outside the

city's mail centre in North Ballarat today.

But Australia Post spokeswoman Nadine Lyford said mail delivery in the region would not be interrupted today and said remaining workers and a casual workforce should ensure it would continue as usual if the strike

continued until Friday.

''All Ballarat mail will be delivered today but there has been effects on mail in Melbourne so there will be delays on any items going in and out of Melbourne,'' she said.

''That will include any mail going interstate or overseas.

''We feel we will be able to maintain the local services should the action continue.

''We do have casuals on at this time of the year in any case and we have other staff coming from other areas.''

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

They also want improved workplace safety conditions.

Ballarat Trades Hall secretary Paul Clempson said workers have been locked in an industrial dispute with the mail provider since 2006, with the most recent round of negotiations breaking down earlier this month and

workers sanctioned by Fair Work Australia to engage in protected industrial action.

''This dispute has been going on for three years,'' he said.

''This isn't about a group of workers saying we want more money, it's about Australia Post guaranteeing jobs. Job security is a major problem.''

The Communications, Electrical and Plumbing Union is lobbying for a four per cent wage increase each year until 2012 and the protection of full-time postal worker positions in their new Enterprise Bargaining Agreement.

Ms Lyford said the organisation was ''very disappointed'' employees chose to invoke their right to strike at the busiest time of the year.

''This has occurred during a period of time when most of the Australian community is depending on us,'' she said.