A French cabinet minister told Montreal Le Devoir that his country wants to renegotiate one particular clause that allows businesses to sue governments.
Matthias Fekl said France will not ratify the agreement if its proposals are not accepted.
Prime Minister Stephen Harper signed the deal last September with then-European Commission president Jose Manuel Barroso and Herman Van Rompuy, who at the time was president of the European Council.
The comprehensive agreement in principle is still being finalized.
A spokesman for International Trade Minister Ed Fast said Monday that both parties are completing a legal review and that the work is on track.
Max Moncaster says the deal will create the equivalent of 80,000 full-time jobs.
"The Canada-EU trade agreement is the most comprehensive and ambitious agreement the world has ever seen, with enormous benefits for Canadians," Moncaster said in an email.
"Both parties are in the processes of completing the legal review. That work is on track and we're looking forward to bringing this agreement into force as soon as possible.
"The EU has repeatedly re-confirmed its commitment to the negotiated outcome. We have every intention of ratifying this agreement and bringing it into force so that our businesses and workers can start to benefit."
The French ambassador to Canada said in March the deal will open up new investment opportunities for Canadian companies, particularly in the area of renewable energy.
Nicolas Chapuis played down concerns that the agreement, known as CETA, might be derailed by recent concerns in Germany and France over the investment-state dispute settlement mechanism.
Also on HuffPost