The French government and CGT union on Sunday dug in their heels amid a wave of strikes and angry street protests against labor reforms, but there were fresh phone contacts between the two sides.
The CGT warned it would continue its campaign of stoppages and demonstrations to pressure the government to scrap plans to make it easier for companies to hire and fire workers.
French Prime Minister Manuel Valls was quoted as saying on Sunday that he was determined not to join a long list of politicians who have conceded defeat to protesters.
"If we gave in to the street and to CGT because we were obsessed over the short term by 2017 (presidential elections), we would lose everything," Valls told French newspaper Le Journal du Dimanche.
In the mid-1990s Prime Minister Alain Juppe triggered France's worst unrest in decades because he would not budge on pension reform but he eventually backed down after weeks of industrial action and protests.
The dispute has sent Valls' approval rating down to 24 percent, its lowest since he became Prime Minister, according to a poll conducted by BVA for Orange et iTELE. Juppe resigned as prime minister in 1996 after his rating dropped below 25 percent.
The government is under pressure to find a solution to the latest stand-off before the June 10 start of the Euro 2016 soccer tournament, which the Force Ouvriere (FO) union had directly threatened to disrupt on Friday.
The prime minister spoke to all trade union leaders by phone on Saturday, government spokesman Stephane Le Foll told France 3 TV. "This is a proof that nothing is completely finished ... We are ready to discuss, but not to give up," he said.
A source close to the prime minister's office said Valls and CGT leader Philippe Martinez had been unable to reach agreement so far. Valls had sought to reassure more supportive unions that he will stand firm on the text of the draft labor bill.
Martinez said in an interview broadcast on BFM TV: "The fact that the prime minister deigns to call the representative of the key French trade union ... is rather a good sign."
The union leader said protests would resume next week.
A plan to overhaul labor rules is crucial to proving France's ability to reform, Finance Minister Michel Sapin said in an interview with Reuters and three European newspapers.
"First and foremost we must be firm," Sapin said. "Doing otherwise would be wrong with respect to (other) labor unions, most of whom support the text."
The more moderate CFDT union backs proposed reform that will allow businesses to lay off staff more easily in hard times but also give unions more power to negotiate unilateral deals with companies rather than national collective agreements.
"There will be no withdrawal of the text ... We are not in '68," government spokesman Stephane Le Foll told France 3 TV, referring to the student-worker uprising in 1968.