About 80 people marched on McGill College Avenue and Sainte-Catherine West calling for more funding for private daycares rather than have new centres open.
During the election campaign, the PQ said it planned to expand the $7-per-day system until every child in need of a daycare had a space.
However, some parents and daycare owners said the Quebec government should lend a hand to the private sector and help fill vacant spots.
Jennifer Park, who runs a centre in Dorval, said she applied for public funding in 2000 but was declined even after she met all of the requirements.
She said the private sector currently has about 16,000 open spots.
The PQ pledged to add 15,000 spots to the current 15,000 spaces in the public system. Parti Québécois Leader Pauline Marois estimated this would cost her government about $177 million.