Record numbers of homeless people have been counted living on the streets of Melbourne, as help services strain under fresh demand created by a "perfect storm" of economic and social pressures in Victoria.

In recent years Melbourne City Council's regular survey of rough sleepers has found a relatively stable homeless population of about 100 people. But the most recent survey has revealed an unexpected 40 per cent increase since the last count in 2012.

A total of 142 homeless people were recorded on a drizzly but mild winter day in June this year. That is the biggest number in the survey's six-year history.

Volunteers also noticed a large number of people sleeping outside the traditional count area, including in public toilets in Docklands and Royal Park, meaning the actual figure is likely to be much higher.

Key homeless services say the count results are evidence of a wider, worrying trend.