The University of Toronto's 2,500 teaching assistants are starting their semester on the picket line.
They are joining colleagues at McMaster University in nearby Hamilton who have been on strike since December 3.
The disputes centre on wages and benefits, but the cost of tuition is an underlying factor. Graduate and postgraduate teaching assistants say that their wages must reflect the rising costs of the studies that make them eligible to do their jobs.
The average annual tuition fee for a Canadian graduate student is Can$3,688 (Pounds 1,550), up 70 per cent from 1994-95, when a graduate student paid an average of Can$2,184.
Hayssam Hulays, spokesman for Toronto's strikers, said his colleagues used to earn enough to pay their tuition. Now they do the same amount of work but finish the year owing Can$1,000 in fees.
"Our members are having to visit the food bank on campus, work at Starbucks at weekends or drop out," said Mr Hulays.
Toronto's teaching assistants are looking at the United States model under which their tuition is waived. They are asking for a wage increase from Can$29.40 to Can$35.95 an hour, which would approximate to wages at another Toronto university, York.
University of Toronto vice-president Michael Finlayson said it is unfair to make a comparison with York University, where graduate students do not have as many opportunities to earn additional research money.
Toronto has refused to negotiate tuition, saying it will create two classes of students. But the assistants retort that faculty staff already receive tuition waivers for their children - a deal their union negotiated when there was a wage squeeze, Mr Finlayson said.
Toronto's administration said the money could be better spent on hiring 160 new staff members. Provost Adel Sedra has asked departments to hold off on signing new contracts for the semester if strike action went ahead.
The union claims this move is illegal.
There are at least six other universities that have either gone through difficult negotiations with their teaching assistants or that are trying to avoid a strike action.
Susan Wilcox, who co-wrote a handbook for teaching assistants and advises faculty, administrators and teaching assistants at Queen's University, admits some teaching assistants are finding less time to teach.
But she said the confrontations facing universities and their assistants would be partly alleviated by more training. She also thinks clearer communication between professors and assistants is needed. "Faculty don't have enough meetings with teaching assistants," she said.