Dutch trade union workers will extend their strike at Royal Dutch Shell’s Pernis oil refinery in Rotterdam, according to a Reuters report. Spokesman Egbert Schellenberg said on Tuesday that the strike would decrease production to 65 percent of capacity. The strike will continue until Shell initiates an offer that could open up wage negotiations, Schellenberg said.

Shell has not made a proposal that aims to address wage increases. Unions said that the oil company’s lack of response has motivated workers to stop their activities at Europe’s largest refinery and chemical plants in the Netherlands since April 8. Schellenberg said that the strike will extend beyond the Pernis refinery to the Moerdijk facility.

Workers want Shell to raise their pay 5 percent, but the corporation has only offered an increase of 4.5 percent that will be spread over two years. On Monday, striking workers shut down a thermal gasoline installation at Pernis, according to Reuters.