A Melbourne council’s “number one” priority is cracking down on dog walkers who do not carry plastic bags to pick up their pooches’ number twos.

Unprepared owners face a $200 fine for walking pets with no poo-bag on hand, with council officers in south-east Melbourne empowered to approach and question potential offenders.

Residents of suburban Berwick, Cranbourne, Narre Warren and Hallam could also be fined $500, up $300 from the previous penalty, if they fail to bin doggy business.

“The onus is clearly put back on the people who own dogs to do the right thing,” the City of Casey mayor, Geoff Ablett, told ABC radio on Wednesday. “For those who don’t, you could end up copping a harsh fine.”

The council revised its animal waste penalties in late November after complaints from “fed up” ratepayers, Ablett said.

“This has been the number one priority, from the animal management side of things, that people want to see changed,” he said. “Responsible dog owners think it’s a great thing, the residents think it’s a great thing.”

But local dog-walker Ben Smith questioned the severity of the fines and how the bag law would be enforced.

“What if they go twice? Are you going to take three or four [bags]?” the Cranbourne East Dog Owners Facebook group founder told 3AW, noting the council did not provide free bags at a local dog park. “Where do you draw the line?”