Royal Dutch Shell has been hit by the departure of several clean energy executives amid a split over how far and fast the oil giant should shift towards greener fuels.┬áThe wave of resignations comes just weeks before Shell is set to announce its strategy for the energy transition. Some executives have pushed for a more aggressive shift from oil but top management is more inclined to stick closer to the company’s current path, according to four people familiar with the matter.

Marc van Gerven, who headed the solar, storage and on-shore wind businesses at Shell, Eric Bradley, who worked in Shell’s distributed energy division, and Katherine Dixon, a leader in its energy transition strategy team, have all left the company in recent weeks.Dorine Bosman, Shell’s vice-president for offshore wind, is also due to leave the company. Several other top executives in the clean energy part of the business also plan to exit in the coming months, two of the people said.

“People are really questioning if there will be any change at all,” said one of the people familiar with the internal tensions. “Part of the frustration is that you see the potential, but the mindset isn’t there among senior leaders for anything radical.”

Ben van Beurden, chief executive, has said investment into lower-carbon businesses such as biofuels and solar power “needs to accelerate”. However, he has also said that oil will continue to be a huge cash generator and the company will expand its gas division. “There is going to be a place for our upstream business for many decades to come,” he recently told a conference.

“I don’t know how we are going to transition without wholesale change at Shell. We don’t have the culture or that level of flexibility to do it,” said another person familiar with the internal split. “I wouldn’t be surprised if we see more high-profile departures. ”