The problem of window-washers in South Auckland is being described as worse than it's ever been before.

Business owners are blaming a vague new bylaw for a sharp rise in the number of window-washers on city streets.

Manukau Central Business Association's Kerry Burridge says people are being attacked and intimidated.

"Please don't pay would be my message. Lock your doors and wind up your windows as you come up to one these intersections, and just shake your head and say no."

Ms Burridge says a vague new bylaw has made the problem worse than ever before.

"We're caught between council, who won't change the bylaw, and on the other side police who are unable to enforce the bylaw."