Workers at three of French oil company Total’s  North Sea oil and gas platforms will go ahead with a 24-hour strike on Monday despite holding talks with the company on Thursday in a dispute over pay and conditions, the Unite union said.

The three platforms are Alwyn, Elgin and Dunbar.

“The scheduled 24-hour stoppage on Monday (20 August) will still go ahead as planned,” Unite said in an emailed statement.

The workers are striking over proposed changes to their working rotas and pay.

The union said its officials had met representatives from Total on Thursday where the union made a series of counter-proposals, to be discussed at talks scheduled for Aug. 23.

Unite said further strikes are planned for Sept. 3, Sept. 17, Oct. 1, Oct. 15 and Oct. 29.

The fields account for about 10 percent of Britain’s gas output, while their oil production contributes about 45,000 to 50,000 barrels per day (bpd) to the Forties and Brent Blend crude streams.

Workers have already held four strikes at the sites as part of the dispute.

The latest, a 12-hour strike on Aug. 13, contributed to a near 4 percent rise in prompt British wholesale gas prices.