Opec will this week seek assurances from some of the world’s biggest oil consumers that they will maintain their demand as the members of the oil cartel come under intense pressure to boost investment in production capacity.

The call, to be made at a summit of the Organisation of the Petroleum Exporting Countries in Riyadh at the weekend, could boost long-term prices as investors worry the oil cartel will not invest enough to meet consumption in the face of growing demand from the likes of China and India.