Quebec Treasury Board president Monique Gagnon-Tremblay says the unions must be realistic in their demands. (CBC) (CBC)

The Quebec government is calling on the province’s biggest public sector unions to take part in a negotiating blitz before the expiry of their members' collective agreement at the end of the month.

Treasury Board president Monique Gagnon-Tremblay made the appeal in a statement issued Friday, one day before the common union front is expected to hold a protest in downtown Montreal.

The minister is also calling on the unions to be "more realistic" in their demands.

The demands tabled by the unions in October would cost more than $8 billion dollars over three years, but the government is facing serious economic challenges and hopes to balance its budget by 2013-2014, said Gagnon-Tremblay.

"I still believe in a negotiated agreement and in the hope of reaching one I am proposing a negotiating blitz," said Gagnon-Tremblay.

"The government is ready to resolve pressing problems, notably those related to the work of nurses, to the support of teachers — particularly those working with special needs students, in order to improve school success."

The government is also willing to work with employees to better organize the work done by civil service workers, she said.

The pace of negotiations with the government continues at a slow pace, said the president of the province’s biggest teachers union during a news conference Friday.

There is a $2 billion difference between the unions’ demands and what the government is offering, said CSQ president Réjean Parent.

The collective agreement between Quebec and its some 500,000 public sector workers expires March 31.