Nearly one in five Alberta workers earns $15 per hour or less, Public Interest Alberta reported Thursday in a pre-Labour Day look at low-wage earners.

Statistics Canada data compiled by the advocacy group, in partnership with the Alberta College of Social Workers, shows that for the year ended June 30, there were 354,700 workers in Alberta earning $15 an hour or less.

Joel French, executive director of Public Interest Alberta (CBC ) Sixty per cent of low-wage Alberta workers are women, the data shows, and 77 per cent are age 20 or older. More than 22 per cent of low-wage workers are 45 or older.

"The image of a teenager living in their parents' basement and working just to earn extra spending money is not the reality for most low-wage workers," said Joel French, executive director of Public Interest Alberta.

"Most of these workers are in their prime earning years and are at the stage where they are planning for, or are already supporting, families."

French praised Alberta's NDP government for taking steps to increase the minimum wage.

The current minimum wage, $11.20 per hour, will increase to $12.20 on Oct. 1. (The current $10.70 minimum for liquor servers will be abolished as of that date.)

Alberta's minimum wage will increase to $13.60 on Oct. 1, 2017, and to $15 on Oct. 1, 2018.

Bringing the minimum hourly rate up to $15 "will make a significant difference for more than 350,000 Albertans and their families," French said.

He challenged opposition parties to lay out their own plans for taking care of low-wage workers "who are just scraping by and are trying to support their families in this province at a time where jobs are even more scarce and times are even more challenging than they were in the past."

The data shows: