Ontario's child care sector would "welcome" the $100-million investment that New Democrats are promising, but a prominent advocate says it's not enough money to address all outstanding issues.

On Mother's Day, NDP Leader Andrea Horwath announced that if her party forms the next government it would provide a one-time $100-million cash infusion to "stabilize" the province's child-care system.

The NDP would also index current annual child-care funding to the rate of inflation.

Martha Friendly, the executive director of the Childcare Resource and Research Unit, said that she and other advocates are still trying to figure out the full significance of the NDP pledge.

"I'm assuming that there is more to come," she told CBC News in an interview today.

Friendly said that advocates in Ontario believe there is a need to spend $300 million to address child-care issues in the province, which include boosting the wages of child-care workers.

Horwath said on the weekend that the New Democrats had long pushed for wage increases for child-care workers and that was something they would pursue if elected into government.

"The $100 million is separate from the commitment to make sure the wages are increased," Horwath said.

Earlier Monday, Ontario Liberal Leader Kathleen Wynne told CBC Radio's Metro Morning that the budget her party brought forward had earmarked $300 million for child care over a three-year period, as well as a wage increase for workers.

But, Wynne said, the New Democrats made it clear they would vote against the budget.

The New Democrats' decision not to support the budget put Ontario on a path to the polls, as the minority Liberals were not going to get support from the Progressive Conservatives either. Wynne chose to face voters instead rather than wait to see her budget formally rejected.

The June 12 election is a month away. At the time of dissolution, the New Democrats held 21 of the 107 seats in the Ontario legislature. The Liberals had 48 and the Progressive Conservatives had 37. One seat was vacant.

With a report from the CBC's Stephanie Matteis