The Autonomous Teachers Federation (FAE) and the CSQ are calling on Quebec's provincial government to postpone the implementation of pre-kindergarten throughout Quebec.
The Legault government's Bill 5 will order all elementary schools to offer pre-kindergarten to four-year-olds as of the 2020-21 school year.
The FAE said that the idea which started as a pilot project during the Marois government for schools in disadvantaged neighbourhoods has yet to be implemented in all such neighbourhoods in Quebec.
The CSQ said the government should concentrate on making pre-K available to those children who will need help adapting to a school environment and will need remedial training before kindergarten.
That basic training includes such things as using scissors, holding pencils and crayons, and learning how to behave in a classroom and play with others.
The FAE, which represents 44,000 teachers, says that rushing pre-K will create even more stress on those children who lack those essential skills.
Other critics have said the plan to institute universal pre-K will mean schools that are already overcrowded will have even less room, and note there just are not enough trained teachers to do the job.
The Federation des transporteurs par autobus also said it worried about the safety of four-year-olds, saying many children that age are too small to easily walk up and down steps, to get in and out of bus seats, and to remember safety rules and regulations.
The bus drivers' group said children that age also frequently slip out of the standard bus seats, and so it has frequently been transporting very young children in special buses.