French refinery workers at Total (FP.PA) staged a fourth day of strike on Monday due to a row with management over annual pay increases, with production units gradually shutting down at the Gonfreville and La Mede plants, union officials said.

“Negotiations with management are still blocked,” a CGT official said. At Gonfreville, 70 percent of workers were on strike, he said.

However, the hardline CGT union has been overtaken by the more moderate CFDT union at the last union elections at Total’s refining branch.

“We will vote early afternoon on whether or not to accept the management’s proposal. We are consulting our teams, but the trend seems to be for an agreement (with management),” the CFDT co-coordinator at Total’s refineries said.

The endorsement of two different union organizations is needed for a deal to go through. The moderate CGC has already said it would sign the deal with management. An agreement would leave the CGT isolated in its action.

The gasoline-producing unit at the 339,000 barrel per day (bpd) Gonfreville refinery in Normandy, France’s largest, was due to stop at 0900 GMT (5:00 a.m. EST), the CGT union official said.

Units were gradually shutting down at the 155,000-bpd La Mede plant near Marseille, another CGT official said, adding it would take four to five days before a complete shutdown.

Similar actions have taken place in previous years without leading to prolonged strikes.

Total was not immediately available for comment.

Suorce: Reuters (Reporting by Michel Rose and Muriel Boselli; editing by Gus Trompiz and Louise Heavens)